# Why DECA is more important than we think



## BudShark (Aug 11, 2003)

DECA - which is really MoCA in a different bandwidth to accomodate DirecTVs system - is critical to the implementation of MRV, and more specifically Whole Home DVRs. It is NOT just an "easier installation", a way to "force upgrades", a way to 'avoid support headaches" or any of those things. DECA is going to be REQUIRED to fulfill DirecTVs plans.

Built into the MoCA standards at the Layer 1 and Layer 2 levels are PQoS, Scheduled transmission slots, and bandwidth reservation. These are not just buzz terms, they are critical to control an even flow of video, data, control schemes for trick play, and ultimately, multiple streams from one server. In an Ethernet environment, these features are not available to DirecTV.

There are several white papers/documents we all should review and be familiar with. I would ask, before you comment on my "assumptions" or another persons that you read these articles. Most of the assumptions about Ethernet or MoCA come from not looking at the specific implementation and usage of MoCA - especially in DirecTVs plans.

First up is an overview of MoCA and what it offers, more than installation advantages (which is one of them): http://www.mocalliance.org/industry/presentations/2007_11_14_TechConference/docs/MoCAProtocols.pdf

Next up is a detailed explanation of PQoS in MoCA implementations and comparison to ethernet QoS and application QoS: http://www.mocalliance.org/industry/white_papers/PQoS_White_Paper.pdf

And finally, the DBSTalk DECA First Look: http://www.dbstalk.com/showthread.php?t=170910

I will limit repeating what is in those and provide three summarized reasons why DECA is critical to DirecTVs plans, and we need to properly reflect the advantages of DECA and stop with the FUD.

1) Ethernet is a contention based network topology. While many people point to switches, full duplex, and other mechanisms that reduce/minimize/eliminate, these items can not be guaranteed in a customer environment. What DECA provides is a mechanism to guarantee bandwidth, priority, consistent packet delivery, without contention (collisions, bandwidth starvation due to file transfer bursts, etc)
2) Scaling problems in customer locations. Most customers have wireless routers or vendor provided routers installed at the head end of their network. These routers typically have only 4 ports. The methods by which customers have "expanded" their networks to accomodate HR2x, H2x, PS3, XBox360, Blu-Ray Players, Roku, etc. vary widely and can include undesirable items such as daisy chained switches, older hubs, and over subscribed uplinks (having 3 clients at 100Mb, connected to a switch with a 100Mb uplink is over subscription). With MoCA, the expansion is irrelevant due to the ability to handle the COAX environment with splitters, the consistent delivery of bandwidth, and the network control method of grant/request.
3) DirecTVs plans include not just MRV, but a single server delivering video content around the home, and ultimately using the RVU effort to actually paint the DirecTV GUI without the end device having to be a DirecTV set top box or device. In this scenario, an Ethernet network would need to manage the bandwidth for the streams, GUI painting, Playlist output, and other data. In addition, the environment would be susceptible to traffic from DLNA servers, Media discovery software, and other devices. Ethernet is not designed to handle the prioritization or bandwidth control - in an Ethernet environment there are 2 solutions. You either throw bandwidth at it or you focus on the server side to manage its connections (which is what most web services and companies use). DirecTV can't manage your ethernet bandwidth or devices, and the HR2x platform is not designed to be a server level device on par with what you have web services or enterprise applications. With MoCA, the technology itself manages the prioritization and queueing and the app/server simply indicates the traffic type (video, audio, control, data, etc).

I am posting this because I think its important for our community to understand A) What MoCA/DECA really is B) Realize that its not simply an easier support/installation method (although it clearly is easier to install/support for DirecTV) and C) Understand why it is important for this change to happen.

In full disclosure, I have tested both Ethernet and DECA. My Ethernet network has worked, and I have stated as much on these forums. I am not "anti-Ethernet", and I have a lot of experience with Ethernet. However, I also do not think Ethernet would be a sufficient answer for what DirecTV wants to do. I believe as we add more streams to a server, as we add RVU a home based ethernet network would not be sufficient. The bandwidth might be there (100Mb), but the prioritization, likelihood of physical layer problems at most peoples homes, and error control/error recovery/contention would prove to be too much to make a reliable infrastructure.

MoCA/DECA on the other hand will not be susceptible to physical layer problems, there will be guaranteed bandwidth for video streaming and prioritization for trick play, and no issues around error control/contention. In addition, it is a consistent platform for installation/support.

Hopefully, this opens a few peoples eyes to why DECA and opportunities over ethernet.


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## BudShark (Aug 11, 2003)

1) *Most homes have routers/switches - so contention and collisions are not an issue - right?*
A: Not necessarily. Many items come into play within this scenario. Is the HR homerunned back to the switch? Was an existing device (hub or switch) added at the media cabinet to accomodate the HR and Blu-Ray player? Are there physical layer (cabling) problems in the home? Did the devices successfully negotiate full-duplex? Was the router ever "forced" to 10/half or 100/half to accomodate an issue? Any number of items affect whether or not a home network has a truly collision free implementation.

2) *Ethernet has more than enough bandwidth*
A: Bandwidth yes, prioritization and control of that bandwidth? No. What DirecTV is moving towards is a video distribution system, with control and potentially GUI painting - all within a home network. On Ethernet, iTunes doing a poll for partner media servers, your HD video stream to the bedroom, the GUI being painted in the Family room, and the playlist sort just performed all have the same priority. That HD video stream is likely to be impacted - particularly by a bandwidth burst of items like row query results and GUI painting. With MoCA/DECA, the video can be given a priority of 2, GUI painting 3, Playlist sort 4, and Trickplay control 1... all other data is best case. So within that same scenario in the DECA cloud, a Pause would make it through in all scenarios, your video streams would never be interrupted, and the rest of the data would flow regularly, but only after the trickplay and video bandwidth needs were satisfied.

3) *My Ethernet network works! I wired my home. It should be sufficient, why doesn't DirecTV fix their stuff?*
A: I won't answer for DirecTV. I will answer that many hobbyists and professionals COULD manage to build a sufficient Ethernet network without contention, over-subscription, and physical layer problems. In this best case scenario, a multi-stream, RVU setup might work. In fact, a design could be set in place to ensure it works using specific equipment that uses various QoS features. But, the requirements for this, the variability, and the number of customers willing to make this level of effort when a valid, tested, and architected solution is available makes this a non-solution.

4) *Can I use my existing Ethernet network for MRV after the beta period?*
A: The current response through the moderators on DBSTalk is, yes. You will have to pay the monthly MRV fee and you will receive no technical support for MRV from DirecTV.


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## BudShark (Aug 11, 2003)

Placeholder


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## transam98 (Dec 2, 2009)

*yawn*


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## barryb (Aug 27, 2007)

transam98 said:


> *yawn*


Can we work on being a bit more respectful? Please?


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## Doug Brott (Jul 12, 2006)

Thanks BudShark


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## P Smith (Jul 25, 2002)

transam98 said:


> *yawn*


It's for advanced ppl here - not for DTV developers. 

Perhaps the thread belong to Installers Forum ?


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## Avder (Feb 6, 2010)

So, two questions here.

1. Is DirecTV going to mandate use of DECA in order to use MRV? That is, are they going to take away the Ethernet option entirely?

2. I've heard that DECA will make it so you can no longer diplex OTA signals on the same cable as Satellite. Is that correct?


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## Shades228 (Mar 18, 2008)

1. No

2. Yes


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## CliffV (Jan 24, 2006)

DECA is clearly the right answer for the way DirecTv networks their boxes together for MRV.

I act as the IT guy for many of my friends and family. It is amazing how many networking problems they have. 

DirecTv already has coax wiring between their receivers. By leveraging that network, DirecTv is avoiding all of the problems associated with supporting arbitrary customer ethernets.


Bravo DirecTv.


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## Doug Brott (Jul 12, 2006)

Avder said:


> So, two questions here.
> 
> 1. Is DirecTV going to mandate use of DECA in order to use MRV? That is, are they going to take away the Ethernet option entirely?


Nope .. MRV over your home network will be allowed, DECA is preferred.



> 2. I've heard that DECA will make it so you can no longer diplex OTA signals on the same cable as Satellite. Is that correct?


This is correct, but Diplexing was introducing signal degradation anyway. In many cases (not all grant you), a SWiM upgrade will be taking a DVR down from two cables to 1 cable anyway so the second cable is now free for OTA signals.


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## Avder (Feb 6, 2010)

Doug Brott said:


> a SWiM upgrade will be taking a DVR down from two cables to 1 cable anyway so the second cable is now free for OTA signals.


Or a second reciever so you can make use of your TV's PiP capability...


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## Thaedron (Jun 29, 2007)

Nice writeup. Thank you.

I think your "long view" commentary is definitely headed in the right direction.


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## Mike Bertelson (Jan 24, 2007)

Avder said:


> Or a second reciever so you can make use of your TV's PiP capability...


Or a second DVR to take care of those pesky 1 & 2 minute over runs that networks are playing with. 

Mike


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## BattleScott (Aug 29, 2006)

Doug Brott said:


> Nope .. MRV over your home network will be allowed, DECA is preferred.


Doug,

Has there been an official release on this? If so, can you elaborate on how "allowed" is defined once the BETA is over?
Does this mean that non-DECA installations will be supported going forward at the same level as DECA installations? Not just from the CSR perspective, but for future enhancements, changes etc...

Thanks,
bs


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## mcbeevee (Sep 18, 2006)

I agree DECA is the way to go. My question is...when will it be available to the the general public?


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## BudShark (Aug 11, 2003)

BattleScott said:


> Doug,
> 
> Has there been an official release on this? If so, can you elaborate on how "allowed" is defined once the BETA is over?
> Does this mean that non-DECA installations will be supported going forward at the same level as DECA installations? Not just from the CSR perspective, but for future enhancements, changes etc...
> ...


There is no official official. The word has been it will be "unsupported" by technicians and CSRs and you will still have to pay. You're on your own. And in terms of the future? Anyones guess as to whether or not certain features will work or be dumbed down (only 1 or 2 streams vs. 3 or 4 for example).


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## Billzebub (Jan 2, 2007)

mcbeevee said:


> I agree DECA is the way to go. My question is...when will it be available to the the general public?


I emailed Directv about this and was told that there would be 4 test markets in March and general release in May. These things often change, but it appears the test markets are here in March, so maybe May.


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## Richierich (Jan 10, 2008)

Excellent Thread and Post Mr. Budshark!!!

It is nice to have a general understanding of how Moca/Deca works so I know why it is a better method of video/audio delivery. Thanks for the Writeup.


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## DogLover (Mar 19, 2007)

Avder said:


> Or a second reciever so you can make use of your TV's PiP capability...





MicroBeta said:


> Or a second DVR to take care of those pesky 1 & 2 minute over runs that networks are playing with.
> 
> Mike


I don't want to take this too far off topic, but since the cables can be "split", you could use a splitter on the first cable to feed both boxes. That still leaves the second cable to OTA if needed.


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## Sim-X (Sep 24, 2009)

I don't use OTA and have SWM - Wish they would hurry up and release DECA

Not sure why some people are against DECA - my ethernet network works fine but one of my DVRS I shut off MRV cause it is connected via wireless which sucks. Plus this way ensures my network doesn't get crowded.


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## opfreak (May 8, 2008)

Is DECA good for DTV?
Yes.

Is ethernet capable doing the same thing?
Yes.

Is DECA being overhyped?

I wouldn't call it being overhyped. IMHO, its bashing ethernet unnessiceraly. It looks bad when you make up FUD about a 'competing' solution just to help sell your own.

That FUD is what causes people to get all wound up.

IMHO, the selling points are easy of install & support for DTV & end users. With the POSSIBILITY of a better experance vs ethernet.

Going much futher then that, esspically attempting to throw ethernet under the bus, IMHO is going to far, and just spreading FUD.

Futhermore, white papers CAN provide usefull information, just like then can be little more then marketing. Reading the ones here, their a blend of marketing talk and information. Just because there called white papers doesn't give them more validity of their claims.


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## Doug Brott (Jul 12, 2006)

opfreak said:


> Going much futher then that, esspically attempting to throw ethernet under the bus, IMHO is going to far, and just spreading FUD.


Who's throwing Ethernet under the bus? Ethernet is a great general purpose medium. The point here is that DECA is optimized for video streaming and trick plays - Ethernet is not. Yeah, Ethernet will work, but DECA is the right tool for the job. You can use a flat head screwdriver on a phillips head screw but it doesn't mean it's the right tool.


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## BudShark (Aug 11, 2003)

opfreak said:


> Is DECA good for DTV?
> Yes.
> 
> Is ethernet capable doing the same thing?
> ...


Please explain/show where there is FUD. I'd be glad to clear it up and/or modify the original document. No one threw ethernet under the bus, however, there are limitations in its inherent design and implementation in home networks that makes it less than ideal for multi-streams of video with time sensitive control mechanisms like trick-play layered on top.


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## dsw2112 (Jun 13, 2009)

opfreak said:


> I wouldn't call it being overhyped. IMHO, its bashing ethernet unnessiceraly. It looks bad when *you* make up FUD about a 'competing' solution just to help sell *your own*.
> 
> That FUD is what causes people to get all wound up.


Just curious who the "you" and "your own" refer to... You're falling into the classic argument fallacy if you're substituting "you" to represent D*, because clearly the people here do not represent "official" D* policies. I'm also pretty sure nobody on this site "owns" DECA to be able to sell it. I haven't seen anything from D* stating what you've posted, only info from DBStalkers... In fact MRV over ethernet will be allowed by D* so apparently it's not all that bad...


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## joed32 (Jul 27, 2006)

Sim-X said:


> I don't use OTA and have SWM - Wish they would hurry up and release DECA
> 
> Not sure why some people are against DECA - my ethernet network works fine but one of my DVRS I shut off MRV cause it is connected via wireless which sucks. Plus this way ensures my network doesn't get crowded.


Most of us don't have SWM and would have to pay to have that installed plus DECA. That's what we're against.


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## bobnielsen (Jun 29, 2006)

joed32 said:


> Most of us don't have SWM and would have to pay to have that installed plus DECA. That's what we're against.


In that case, and if MRV is working for you, there is no reason to switch to DECA.


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## joed32 (Jul 27, 2006)

bobnielsen said:


> In that case, and if MRV is working for you, there is no reason to switch to DECA.


Thanks, I just wanted to say that most people are not against DECA, just against the cost. I may get it someday but for now I'm happy.


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## bb37 (Dec 27, 2007)

Doug Brott said:


> Yeah, Ethernet will work, but DECA is the right tool for the job.


When my employer first started networking HVAC controllers, they went with ArcNet because it was a deterministic network architecture that our engineers thought was better suited for real-time data acquisition and control. When we networked a building, our controls network was stand-alone and separate from the customer's business network.

But, our customers wanted Ethernet. They wanted our control systems to ride on their business network because it was less expensive (one network is less expensive to install and maintain than two) and it was easier to integrate our control systems with their business systems. So, we adapted and now all of our controllers are Ethernet.

We are now running into customers who find that they don't want us on their network because of the traffic our systems cause. And, we had one customer whose Ethernet network was so cobbled together that a problem on their network crashed our controllers resulting in some loss of data. So, now we have customers who insist that we install our own network.

Bottom line is that that networks should be designed for technical reasons before you start figuring cost and preferences. If there are good technical reasons for DECA over Ethernet, then we need to give DECA serious consideration.


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## Kansas Zephyr (Jun 30, 2007)

I think that DECA is wonderful.

But, why did they use the OTA spectrum? The cost to properly run additional coax for OTA to all of my current and future IRDs, isn't worth the return. Diplexing is my best choice, since my home was originally wired for "traditional cable" with single runs from an exterior box.

Living in the Plains , rain-fade isn't a trivial issue. OTA is my only insurance that my family can watch severe weather coverage. Plus, DVRing OTA ensures no fade problems.

I only had D* on a single HDTV for Sunday Ticket. However, the ability to diplex, and DVR OTA convinced me to drop cable and spread D* throughout the home. 

So, if I implement MRV it will be via my home network, to preserve OTA diplexing. Again, I think that DECA is great...but just not for me at this time.

I've made quite an investment in D*. I hope they realize the value in having the OTA option. Yeah...I know the usage is low. But, I'll bet that it's used by some of their better paying customers, since you need HD to be able to even use it.

I can only hope that the future D* home server will include several OTA tuners. Then, I can only worry about feeding OTA to a single location, allowing DECA to pass the signals to the other set-tops.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> I think that DECA is wonderful.
> 
> But, why did they use the OTA spectrum?


I guess first I'd ask what part of the spectrum you wanted them to use?
DECA is MoCA [but at a different frequency]. MoCA uses 1100 MHz for CATV, since it's above their bands.
DirecTV couldn't use 1100 MHz. DECA is ½ the MoCA frequency, so this may have been an easy change in the chips.
With OTA & SWiM, there really isn't much bandwidth "open". Since the digital change over, 700-970 MHz, could have been used, but this may have required much more changes to the chips, and not been as cost effective.


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## wilbur_the_goose (Aug 16, 2006)

I love the info, Mr. budshark. Thanks!


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> With OTA & SWiM, there really isn't much bandwidth "open". *Since the digital change over, 700-970 MHz, could have been used*, but this may have required much more changes to the chips, and not been as cost effective.


Exactly, with the removal of channels 52-69 (698-806 MHz) from the OTA service, there is plenty of room for DECA without OTA interference.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> Exactly, with the removal of channels 52-69 (698-806 MHz) from the OTA service, there is plenty of room for DECA without OTA interference.


And I see you didn't highlight the cost factor.


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> And I see you didn't highlight the cost factor.


...and your point?

You did ask "What spectrum would they use?".

Your cost factor is speculative, isn't it? Or, do you have knowledge?

The spectrum availability is fact.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> ...and your point?
> 
> You did ask "What spectrum would they use?".
> 
> ...


I don't have exact knowledge, but to redesign a chip isn't as cheap as adding a divider and knocking the output frequency in half.


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> I don't have exact knowledge, but to redesign a chip isn't as cheap as adding a divider and knocking the output frequency in half.


Yeah...and?

Sorry, I only highlighted the spectrum portion of your reply.


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## Doug Brott (Jul 12, 2006)

Kansas Zephyr said:


> Yeah...and?


 ... and OTA is not used by that many people, an unfortunate thing, but why pay lots more for many when it only benefits few? .. Sounds like a business decision.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> Yeah...and?
> 
> Sorry, I only highlighted the spectrum portion of your reply.


I guess reading and connecting the dots doesn't work, so:
The chips used for DECA are based off the chips used for MoCA. Modifying them to use half the frequency of MoCA, is cheaper than a complete redesign of a new chip.
DirecTV decided to go with the cheaper option and not worry about those few customers that have been using the unsupported diplexing with SWiM.
As with everything in business, it comes down to costs.


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## Kansas Zephyr (Jun 30, 2007)

Doug Brott said:


> ... and OTA is not used by that many people, an unfortunate thing, but why pay lots more for many when it only benefits few? .. Sounds like a business decision.


I hear ya. I get it.

But, would it be "lots more"? Again, that's just guessing.

Connect those VOS.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> I hear ya. I get it.
> 
> But, would it be "lots more"? Again, that's just guessing.
> 
> Connect those VOS.


Have you had much experience in chip design?
If you can make changes on the top layer of the silicon, it's fairly easy.
If you need to make these in the lower layers, then you need to re-layout the masks and re-fab the wafers.


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> If you can make changes on the top layer of the silicon, it's fairly easy.
> If you need to make these in the lower layers, then you need to re-layout the masks and re-fab the wafers.


Then perhaps you can tell us what the estimated cost would be in each case? 

No...I've got no clue about chip design and manufacturing. Got me.


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## Kansas Zephyr (Jun 30, 2007)

Doug Brott said:


> ... and OTA is not used by that many people, an unfortunate thing, but why pay lots more for many when it only benefits few? .. Sounds like a business decision.


I also wonder about those D* customers in areas of high OTA signal strength.

Could stray RF introduced into the closed system, via bad shielding, etc. be problematic for DECA?


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## Doug Brott (Jul 12, 2006)

Kansas Zephyr said:


> I also wonder about those D* customers in areas of high OTA signal strength.
> 
> Could stray RF introduced into the closed system, via bad shielding, etc. be problematic for DECA?


I'm not an RF guy, but this seems like a stretch.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> I also wonder about those D* customers in areas of high OTA signal strength.
> 
> Could stray RF introduced into the closed system, via bad shielding, etc. be problematic for DECA?


The levels that DECA run, would override any stray OTA signals.
As a matter of fact, DECA must be blocked from an OTA antenna, or you'll have your own mini transmitter. If you happen to have a good high gain directional antenna, you could even find the FCC knocking on your door.


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## Kansas Zephyr (Jun 30, 2007)

Doug Brott said:


> I'm not an RF guy, but this seems like a stretch.


A stretch?

Ask cable customers that lived in areas where the cable company had the analog local stations on the same cable channel as their RF (KXXX channel 4 on cable channel 4, too). If they lived near the transmitter, any bad shielding would produce horrible ghosting, due to the time delay of the OTA versus the cable head-end signals.

Since DECA uses the OTA spectrum, I only ask the question. Do I think this will be a "major issue"...of course not.


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> The levels that DECA run, would override any stray OTA signals.
> As a matter of fact, DECA must be blocked from an OTA antenna, or you'll have your own mini transmitter. If you happen to have a good high gain directional antenna, you could even find the FCC knocking on your door.


Really? That much RF? Any idea how much?


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> A stretch?
> 
> Ask cable customers that lived in areas where the cable company had the analog local stations on the same cable channel as their RF (KXXX channel 4 on cable channel 4, too). If they lived near the transmitter, any bad shielding would produce horrible ghosting, due to the time delay of the OTA versus the cable head-end signals.
> 
> Since DECA uses the OTA spectrum, I only ask the question. Do I think this will be a "major issue"...of course not.


DECA is about 20-30 dB higher than CATV.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> Really? That much RF? Any idea how much?


In the 0 to +5 dBm range.


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> In the 0 to +5 dBm range.


OK...even 25mi away i'm getting up to +8.6dBmV on OTA channels.

You're right about rebroadcasting DECA. Great.

I'm tempted to try DECA with OTA diplexing, just to see what gives in the real world, hoping that the OTA channels around here won't interfere.

With the mast-mounted preamp, I think that it will not pass RF back to the antenna.


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## Avder (Feb 6, 2010)

Do the ethernet ports in the HR boxes support gigabit or just 100 megabit?


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## Mike Bertelson (Jan 24, 2007)

Avder said:


> Do the ethernet ports in the HR boxes support gigabit or just 100 megabit?


10/100 only.

Mike


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## bobnielsen (Jun 29, 2006)

With diplexed OTA, you would have issues with channel 27 and possibly others nearby in frequency.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> OK...even 25mi away i'm getting up to +8.6dBmV on OTA channels.


And 0 dBm = 49 dBmV


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> And 0 dBm = 49 dBmV


Yep...I'm 25mi away.

Think of those close to the towers.

But, yes that's plenty of RF for a closed system. So, it shouldn't be an issue, except for some extreme case, possibly, somewhere.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> Yep...I'm 25mi away.
> 
> Think of those close to the towers.
> 
> But, yes that's plenty of RF for a closed system. So, it shouldn't be an issue, except for some extreme case, possibly, somewhere.


:lol: If you're that close to a tower, you're going to have other problems. :lol:


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> :lol: If you're that close to a tower, you're going to have other problems. :lol:


True dat.

My favorite was a lady who lived next to to a 1070AM antenna farm and bragged about her washing machine/radio!


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## opfreak (May 8, 2008)

Doug Brott said:


> Who's throwing Ethernet under the bus? Ethernet is a great general purpose medium. The point here is that DECA is optimized for video streaming and trick plays - Ethernet is not. Yeah, Ethernet will work, but DECA is the right tool for the job. You can use a flat head screwdriver on a phillips head screw but it doesn't mean it's the right tool.


Your screw driver analogy is the FUD i'm refering to. Theres no need to explain this to FUD spreaders because they wont be convienced, ethernet can be used without problems. However some people dont want to hear that because they've been sold on something shiney and new


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## ZPrime (Feb 16, 2010)

I'd love to see someone tell my QoS/Prioritized Ethernet switch at the office that it "Can't do that" because it's Ethernet and not DECA/MoCA. Our entire IP phone infrastructure would love to hear why it shouldn't be working because the switch shouldn't be able to do QoS. 

While I don't disagree that DECA is a great solution for people w/o existing ethernet infrastructure, I do agree with opfreak -- it's verging on FUD to be yakking about how "OMG Ethernet isn't optimal, DECA is the win." Even if you do have daisychained switches, as long as you aren't trying to copy your DVD library from one PC to another across the single uplink while trying to stream a show, you won't have a problem. We're talking a few MPEG4 streams here. What kind of bandwidth do you think they take up on the satellite feed?

If they have future plans for MRV/DECA, I can understand the need for a more advanced network, but they're going to need more than 100Mbit ports on the boxes for that (and if you read the DECA "whitepaper," it tops out around 175 Mbit right now anyway).

Looking at what the whitepaper _can_ tell us... The latency is terrible. Wired switched Ethernet has a latency around 1ms in most cases. DECA shows an "average" of 3.5ms, and it goes up when you have more than 8 nodes. For things like "interactivity" i.e. trickplay/FF/RW, you want LESS latency, not more. (Granted, I think the media delay is completely dwarfed by the delay of the boxes themselves right now, but my point still stands.)

I hope that DECA drops the encryption portion as well - it's standard in MoCA and completely pointless in a single home DECA setup. In a multi-dwelling environment, not only should it be standard but it needs to be doubled in strength to be worth a crap. 54 bit DES is laughable these days.

A lot of the lines in the whitepaper are hooey. "Fully scheduled MAC - no collisions" -- switched Ethernet is collision-free as well and has been around a LOT longer than MoCA.

I mean, if consumers were using hubs in their homes I'd understand, but it's nearly impossible to buy a hub these days.


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## ChrisWyso (Nov 16, 2005)

Yeah, I'm in that category of "I've set it up and it's running fine." My situation is that my 2 receivers are both in the family room, separated literally by a 1/2" shelf. I have a 3' Cat cable between them. I have no need for DECA, and even if I moved one of those receivers upstairs, I have every room wired already with Cat-5e.

Since it looks like they're gonna be charging $3/month for MRV, I think we can save that $3 and change the inputs on the TV & audio receiver on the remotes ourselves. It's a convenience for us, not a necessity.


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## Mike Bertelson (Jan 24, 2007)

Bigg said:


> If you're already on 100mbit Ethernet, that would be a downgrade.  Of course, if you can't figure out how to drop Cat-5e to your locations, then it would be an upgrade.


How do you figure that would be a downgrade? Have you read the specs and the posts? 

Mike


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## hdtvfan0001 (Jul 28, 2004)

Bigg said:


> If you're already on 100mbit Ethernet, that would be a downgrade.  Of course, if you can't figure out how to drop Cat-5e to your locations, then it would be an upgrade.


DECA is faster and has less collisions for the video streaming process within MRV - so it is an upgrade, not downgrade.

Budshark as a great thread started on this topic it explains the differences and why DECA is better for this application.


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## Mike Bertelson (Jan 24, 2007)

ZPrime said:


> I'd love to see someone tell my QoS/Prioritized Ethernet switch at the office that it "Can't do that" because it's Ethernet and not DECA/MoCA. Our entire IP phone infrastructure would love to hear why it shouldn't be working because the switch shouldn't be able to do QoS.
> 
> While I don't disagree that DECA is a great solution for people w/o existing ethernet infrastructure, I do agree with opfreak -- it's verging on FUD to be yakking about how "OMG Ethernet isn't optimal, DECA is the win." Even if you do have daisychained switches, as long as you aren't trying to copy your DVD library from one PC to another across the single uplink while trying to stream a show, you won't have a problem. We're talking a few MPEG4 streams here. What kind of bandwidth do you think they take up on the satellite feed?
> 
> ...


Hubs are everywhere. A search on Amazon showed eight out sixteen items on the first page alone were hubs not switches. Nearly every time I go over someone's house I see they have hub not a switch. Why, because it's usually the cheapest thing they could find.

You are absolutely correct in that a network as robust as yours (and a lot of ours here) will perform as well or better than DECA...all good points and there's no doubt it's the way to go for you.

However, these kinds of networks are not the norm. For everyone you know with a robust home network there is ten times that many are just plain crap. You'd be amazed at the complete junk I've seen...Cat5 spliced together with wire nuts and electrical tape, wire draped over the electric water heater or fluorescent lights as it runs across the basement, random colored wires on each pin of a connector because "as long as it's the same on the other end you have continuity, right", and all of that connected to a $5, four port hub. :shrug:

My point is that while most of us have properly built, robust networks most people do not, and more likely nothing at all. DECA is a DirecTV's answer to how to provide working, stable MRV to the most people possible. It is impossible for DirecTV to be able to support/repair everyone's networks to get MRV working. Starting with a known, controllable infrastructure solves all those problems...less tech support calls, less trucks rolling to a subs home.

Mike


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## BudShark (Aug 11, 2003)

ZPrime said:


> I'd love to see someone tell my QoS/Prioritized Ethernet switch at the office that it "Can't do that" because it's Ethernet and not DECA/MoCA. Our entire IP phone infrastructure would love to hear why it shouldn't be working because the switch shouldn't be able to do QoS.
> 
> While I don't disagree that DECA is a great solution for people w/o existing ethernet infrastructure, I do agree with opfreak -- it's verging on FUD to be yakking about how "OMG Ethernet isn't optimal, DECA is the win." Even if you do have daisychained switches, as long as you aren't trying to copy your DVD library from one PC to another across the single uplink while trying to stream a show, you won't have a problem. We're talking a few MPEG4 streams here. What kind of bandwidth do you think they take up on the satellite feed?
> 
> ...


First, thank you for your reply. There are many assumptions being batted around and the original post and FAQs tried to illustrate those.

No one has said Ethernet stinks and doesn't work. I have worked with Ethernet for 20 years at a core level at many companies. I know its strengths, and its weaknesses. In fact, in the FAQ I explicity state many hobbyists and professionals could make it work.

WHAT the paper says that so many seem to be missing is that A) Most home ethernet networks are not properly constructed, reliable, full-duplex switched networks.  B) The future state for DirecTV is to have multiple streams, with control schemes, and GUI painting all running from a single server. This approach, and the amount of traffic and its time sensitivity, means home based Ethernet is not a good candidate.

In terms of your specific statements - its obvious you have a grasp of Ethernet which is good and means you are likely able to construct a reliable network. It also means you'll understand my next few statements. Many of the mistakes about Ethernet is to look at networks as a one-size fits all approach. And someone will look at switching and say, see look no collisions. And someone will look at bandwidth and say faster is better. And someone will look at latency and say less is better. A good architect won't say any of those things. He'll ask what your network is intended for.

If I have a 60fps video need with guaranteed bandwidth and delivery, with time sensitive control needs - do I care about 3.5ms vs. 1ms? No - the latency in both cases is sufficient. Do I care about 100Mbps vs 175Mbps vs 1Gbps? No - the bandwidth in all cases is sufficient. I care about my delivery mechanism. Can I get my packet there when I need to? Do I have a mechanism to deliver my Pause request above the priority of a stream in order to ensure a "like local" experience for the end user? What is the mechaism to start a new stream while an existing stream is in place? How do I allocate an equal delivery of raw data?

Are those answers available in Ethernet? Not at its core - it requires hardware (or software) solutions such as 802.1p or other QoS mechanisms. This means I now have to build customers Ethernet networks to exacting standards. Not practical. Or I can use DECA/MoCA - which has the prioritization, QoS, and easy build out I need.

Like you stated - your QoS/Prioritized Ethernet switch works just fine. But you aren't going to come close to finding that in customers home. And you also won't find a single person on here that said it couldn't be done with Ethernet. Just that its impractical for the end game and DECA/MoCA is a better solution.


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## Sixto (Nov 18, 2005)

It seems that there are four scenarios being discussed, possibly all with different performance characteristics and results:

All receivers connected to a single quality Switch. Full Duplex. Most Switches state that they provide full 100mpbs (or 1000mpbs) each direction between two ports. Actual performance varies depending on block size and other factors. 
All Legacy (non-Hx24) receivers connected via DECA dongles/Coax to a single DECA cloud, with a network-DECA for the bridge to the home network.
All Hx24 receivers connected via Coax (no DECA dongles) to a single DECA cloud, with a network-DECA for the bridge to the home network.
Some combination of the above.
I've been assuming (priority order):

#3 (Hx24) may be optimal.
#1 (Ethernet) may be similar (that's the debate here).
#2 (DECA dongles) is connected through the Ethernet port and have yet to see confirmation if similar to #3 (All Hx24 with the same QoS benefits).
#4 (Mixed) may depend on what's in the Cloud, what's outside the Cloud, and how much significant traffic crosses the network-DECA, but it appears that #4 is last, but again depends on traffic.
There's also the future with RVU (with real-time screen control), which I'm ignoring because the future remote nodes may not have an Ethernet port.

It's obvious that all DECA options may be superior when compared to an improperly configured wired networked, or wireless.


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## Steve (Aug 22, 2006)

Sixto said:


> It seems that there are four scenarios being discussed, possibly all with different performance characteristics and results:
> 
> 1. All receivers connected to a *single* quality Switch. Full Duplex. Most Switches state that they provide full 100mpbs (or 1000mpbs) each direction between two ports. Actual performance varies depending on block size and other factors.[...]


Actually in that scenario, if you're using gigabit switches like the DGS-2208 from D-Link, it probably doesn't matter if you need to attach a second or third switch to the first one. That switch is a real bargain at about $45, IMHO.

From the spec sheet:

STANDARDS
+ IEEE 802.3 10Base-T Ethernet
+ IEEE 802.3u 100Base-TX Fast Ethernet
+ IEEE 802.3ab 1000Base-T Gigabit Ethernet
+ IEEE 802.3 Nway Auto-negotiation
+ IEEE 802.3x Flow Control
+ IEEE 802.1p QoS Prioritization

FEATURES
+ Number of Ports: Eight 10/100/1000BASE-T
+ MAC Address Table: 4k
+ Switch Fabric: 16Gbps
+ Packet Buffer Memory: 192KBytes per Device
+ Transmission Method: Store-and-forward
+ Jumbo Frames: Up to 9720 Bytes
+ Cable Diagnostic LEDs

NETWORK DATA TRANSFER RATE
+ Ethernet: 10Mbps (Half-duplex)
+ Ethernet: 20Mbps (Full-duplex)
+ Fast Ethernet: 100Mbps (Half-duplex)
+ Fast Ethernet: 200Mbps (Full-duplex)
+ Gigabit Ethernet: 1000Mbps (Half-duplex)
+ Gigabit Ethernet: 2000Mbps (Full-duplex)


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## Sixto (Nov 18, 2005)

Steve said:


> Actually in that scenario, if you're using gigabit switches like the DGS-2208 from D-Link, it probably doesn't matter if you need to attach a second or third switch to the first one. Just my .02.


Yep, I added "single" just to keep the scenarios clearly defined, without any ambiguity.


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## opfreak (May 8, 2008)

BudShark said:


> Are those answers available in Ethernet? Not at its core - it requires hardware (or software) solutions such as 802.1p or other QoS mechanisms. This means I now have to build customers Ethernet networks to exacting standards. Not practical. Or I can use DECA/MoCA - which has the prioritization, QoS, and easy build out I need.


Thats amazing double talk.

Just think about what you posted.

"This means I now have to build customers Ethernet networks to exacting standards."

"Or I can use DECA/MoCA - which has the prioritization, QoS, and easy build out I need"

What excatly is the difference?

DECA/MoCa is your ethernet system built to "exacting standards."

again, from DTVs POV a DECA system makes sense. But ethernet could work just as well.


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## BudShark (Aug 11, 2003)

opfreak said:


> Thats amazing double talk.
> 
> Just think about what you posted.
> 
> ...


Dude... seriously. *NO ONE SAID ETHERNET COULDN'T WORK. READ. And READ again.*

For Ethernet to provide the same result as MoCA/DECA - people would have to implement QoS, switched, full-duplex environments. Could they? Yes. Have they? Mostly No.

Why are we going around and around. You want to use Ethernet. Go ahead. Have at it. Enjoy.

Is it FUD to tell a customer that buying the D-Link wireless router on sale this weekend at Best Buy and using the Cat5e wiring their builder put in, and then using a switch under their media center to connect their HR20 and Blu-Ray player is a LESS DESIRABLE video distrubtion network than using DECA? No it is not. Its fact.

And in terms of your "whats the difference" - well there would be the fact that MoCA/DECA is a cloud based environment that uses grant/request from a network controller elected upon cloud build vs the more hardware specific requirement of a star topology ethernet network you're proposing. The fact that I would have to implement twice the wiring, install and support an additional piece of equipment (Switch) and ensure that switch had a QoS mechanism such as 802.1p (which is still less than what MoCA/DECA offers), and STILL be subject to customer build out on top of that network that may or may not impact my end quality of service that my customer is paying for.

But yeah... you're right. I'm just double talking.


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## Mike Bertelson (Jan 24, 2007)

opfreak said:


> Thats amazing double talk.
> 
> Just think about what you posted.
> 
> ...


I refer you this post above...

http://www.dbstalk.com/showthread.php?p=2397345#post2397345

It's also about keeping costs down. It's also not about your network or my network. It's about having the same set of hardware/firmware...ease of installation and ease of tech support.

Mike


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## opfreak (May 8, 2008)

BudShark said:


> Dude... seriously. *NO ONE SAID ETHERNET COULDN'T WORK. READ. And READ again.*
> 
> For Ethernet to provide the same result as MoCA/DECA - people would have to implement QoS, switched, full-duplex environments. Could they? Yes. Have they? Mostly No.
> 
> ...


The more you repeat it the more true it becomes right? :nono2:


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## BudShark (Aug 11, 2003)

opfreak said:


> The more you repeat it the more true it becomes right? :nono2:


Dude... seriously. NO ONE SAID ETHERNET COULDN'T WORK. READ. And READ again.

For Ethernet to provide the same result as MoCA/DECA - people would have to implement QoS, switched, full-duplex environments. Could they? Yes. Have they? Mostly No.

Why are we going around and around. You want to use Ethernet. Go ahead. Have at it. Enjoy.

Is it FUD to tell a customer that buying the D-Link wireless router on sale this weekend at Best Buy and using the Cat5e wiring their builder put in, and then using a switch under their media center to connect their HR20 and Blu-Ray player is a LESS DESIRABLE video distrubtion network than using DECA? No it is not. Its fact.

And in terms of your "whats the difference" - well there would be the fact that MoCA/DECA is a cloud based environment that uses grant/request from a network controller elected upon cloud build vs the more hardware specific requirement of a star topology ethernet network you're proposing. The fact that I would have to implement twice the wiring, install and support an additional piece of equipment (Switch) and ensure that switch had a QoS mechanism such as 802.1p (which is still less than what MoCA/DECA offers), and STILL be subject to customer build out on top of that network that may or may not impact my end quality of service that my customer is paying for.

But yeah... you're right. I'm just double talking.


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## opfreak (May 8, 2008)

MicroBeta said:


> It's also about keeping costs down. It's also not about your network or my network. It's about having the same set of hardware/firmware...ease of installation and ease of tech support.
> 
> Mike


I completely argee with that statement

I dont agree with posts by BudShark, because he is attempting to spread FUD about ethernet.


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## veryoldschool (Dec 10, 2006)

BudShark said:


> But yeah... you're right. I'm just double talking.


And I wish you'd stop it. :lol: :lol: :lol:


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## BudShark (Aug 11, 2003)

opfreak said:


> I completely argee with that statement
> 
> I dont agree with posts by BudShark, because he is attempting to spread FUD about ethernet.


Please show me one piece of FUD I've spread about ethernet.


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## LameLefty (Sep 29, 2006)

opfreak said:


> I dont agree with posts by BudShark, because he is attempting to spread FUD about ethernet.


*SPECIFICALLY*, what was FUD about anything he posted?


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## David MacLeod (Jan 29, 2008)

its all about potential. does an average homeowners broadband modem/router have the potential to NOT work as well? yes. 
will a properly designed ethernet solution work? IMO yes, but the key words are properly designed. and someone tossing cheapest switches all over the place with cables built on a whim does not qualify.
does deca have the potential to ALWAYS work, and if not will ALWAYS be supported and corrected by Directv? yes.


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## harsh (Jun 15, 2003)

veryoldschool said:


> I don't have exact knowledge, but to redesign a chip isn't as cheap as adding a divider and knocking the output frequency in half.


Regular MoCA can change frequencies as needed to cooperate with other MoCA installations. One might assume that the frequency could be adjusted in an inexpensive way given the chipset is probably the same.

Does anyone know the Q factor on the band-stop filter? That would certainly lay down some parameters.


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## Doug Brott (Jul 12, 2006)

opfreak said:


> I completely argee with that statement
> 
> I dont agree with posts by BudShark, because he is attempting to spread FUD about ethernet.


Actually, you are incorrect .. DECA is optimized for video streaming and trick plays .. Plain and simple .. Ethernet is optimized for general purpose .. again, plain and simple ..

Both with work, Ethernet is more susceptible to problems .. again, plain and simple.


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## Doug Brott (Jul 12, 2006)

harsh said:


> Regular MoCA can change frequencies as needed to cooperate with other MoCA installations. One might assume that the frequency could be adjusted in an inexpensive way given the chipset is probably the same.
> 
> Does anyone know the Q factor on the band-stop filter? That would certainly lay down some parameters.


I think the point VOS was trying to make is that that assumption one makes could be much more than 'inexpensive' in reality.


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## Sixto (Nov 18, 2005)

The only question that has interested me is whether there's tangible benefit to replacing ($) a fully hardwired properly configured H2x/HR2x Ethernet environment. Also, whether DECA dongles provide the same QoS benefit as and all-Hx24 environment vs all-Ethernet.

For new or mixed environments, especially those with wireless, DECA is the obvious choice.

Also, having significant MRV traffic crossing the network-DECA does not seem optimal.


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## LameLefty (Sep 29, 2006)

Sixto said:


> Also, having significant MRV traffic crossing the network-DECA does not seem optimal.


It's probably not optimal, though I've had three HD streams going through one DECA "bottleneck" without issue (two in to the HR24 and H24, and one out from the HR24). That said, I do have a couple places in my house that would benefit from DECA adapters since I have RG6 going to those rooms and don't have Cat6 run there. Get me some adapters and I'll convert, pronto.


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## Sixto (Nov 18, 2005)

LameLefty said:


> It's probably not optimal, though I've had three HD streams going through one DECA "bottleneck" without issue (two in to the HR24 and H24, and one out from the HR24). That said, I do have a couple places in my house that would benefit from DECA adapters since I have RG6 going to those rooms and don't have Cat6 run there. Get me some adapters and I'll convert, pronto.


Yep, testing did find a limit, but that may no longer exist (haven't tried recently).


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## leww37334 (Sep 19, 2005)

Agree with Sixto, this is totally a matter of $, there are other posts in this forum about the cost of implementing a DECA solution in the rollout test market. The costs seem to be higher than expected. 

In a home with a hardwired CAT5/6 solution that is working perfectly upgrading to this DECA/MOCA solution in order to get a thin client structure that doesn't exist yet seems to be premature.

I believe Directv could take care of the current MRV problems simply by restricting MRV to being a wired solution, and dropping support for wireless. This would take care of a very large percentage of the problems. 

But having said all that I will probably jump on the bandwagon anyway, because I am a sucker for new technology.:lol::lol::lol:


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## opfreak (May 8, 2008)

Doug Brott said:


> Actually, you are incorrect .. DECA is optimized for video streaming and trick plays .. Plain and simple .. Ethernet is optimized for general purpose .. again, plain and simple ..
> 
> Both with work, Ethernet is more susceptible to problems .. again, plain and simple.


Ethernet is more to problems?

and the Coax cable isnt?

Slap on the same controls you have with MoCa/Deca on ethernet and your problems are solved.


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## BudShark (Aug 11, 2003)

opfreak said:


> Ethernet is more susceptible to problems?
> 
> and the Coax cable isnt?
> 
> Slap on the same controls you have with MoCa/Deca on ethernet and your problems are solved.


Actually not true.

MoCA was built within certain specifications to handle loops, splitters, and a variety of expected wiring conditions, including but not limited to RG59, RG6, RG6U, crimp connections, etc. In other words, its more tolerant of physical layer.

First off you can't "slap" on the same controls you have with MoCA/DECA. One is contention based and the other is a scheduled/request delivery. Fundamentally that changes them and makes Ethernet dependent on star topology, switches and full-duplex. MoCA/DECA does not have this requirement. It can be a star back to a splitter, it can be a loop, or it can be a disjointed/daisy chained physical layer. Second off, there isn't a standard for Ethernet today that handles the packet priority, bandwidth reservation, and scheduling. 802.1p is a QoS standard, but it has limitations and is not as robust - and it doesn't include the reservation or scheduling components. G.hn is a standard proposed (based off what is in MoCA/DECA by the way) to bring a QoS physical layer specification for multimedia purposes to physical layers - but its no where near released or usable at this point.

Sorry, but this statement shows just how little you understand about what the real difference is between Ethernet and MoCA/DECA. Neither is a replacement for the other, and both can do what the other does. But, in the end, they are both geared towards different needs and both are imperfect solutions for the other. MoCA/DECA happens to be a better video streaming physical layer - the simplified cabling and existing infrastructure benefits aside.


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## Thaedron (Jun 29, 2007)

MicroBeta said:


> It's also about keeping costs down. It's also not about your network or my network. It's about having the same set of hardware/firmware...ease of installation and ease of tech support.
> 
> Mike


Hit the nail very squarely on the head.

The properly switched, wired and configured ethernet network should in most every case be able to support MRV just as well as DECA will be able to. IMO, DirecTV doesn't want to get into the network installation business. The outstanding question would be would ethernet just as effectively support the longer term plans for STBs that DirecTV seems to have. Maybe yes, maybe no. DECA, seems mostly yes.

Though we seem to keep driving this as a technological debate. IMHO, it's not. It's about the total cost to serve the customer, which from DirecTV's perspective is much more signifcantly driven by the installation time, complexity and on-going support costs.

*Take the following example:*
Installation Scheduled for Mr. and Mrs. Smith to setup DirecTV @ 3 locations (2 HD DVRs and one HD receiver) all with MRV. Their home is wired for cable with single coax to all three locations. They have a cable modem connected directly to their PC (no home network).

Scenario A
Use SWM / DECA to connect all three receivers/DVRs with just the existing single-line to each location, which will also fully support MRV.

Scenario B
Install the receivers / DVRs with just a WB68 multi-switch.
Run additional coax to the DVR locations.
Install a 4-port ethernet switch.
Run network lines to each location.

Which do you think would be more cost effective in the long run to support...???

The arguements that we're beating each up over aren't about us... The arguement is about the MILLIONS of less technological households existing out there, or yet to be installed.

It's a no-brainer IMO.


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## BudShark (Aug 11, 2003)

Thaedron said:


> The arguements that we're beating each up over aren't about us... The arguement is about the MILLIONS of less technological households existing out there, or yet to be installed.
> 
> It's a no-brainer IMO.


You are absolutely correct. At the root of this is the fact that DirecTV is going to do whatever puts them in the best position to make money, and a solution that is more consistent and cheaper to support/install will do that.

The reason for my thread, and the reason I am working to counter so many of the comments, is because there was a general feeling that DECA is less than Ethernet and that Ethernet was a better solution. Hopefully the thread opens some peoples eyes that DECA is not a "poor mans way to run Ethernet over coax" - but actually a different physical layer designed specifically for the purposes DirecTV intends to use it for.


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## Thaedron (Jun 29, 2007)

BudShark said:


> The reason for my thread, and the reason I am working to counter so many of the comments, is because there was a general feeling that DECA is less than Ethernet and that Ethernet was a better solution. Hopefully the thread opens some peoples eyes that DECA is not a "poor mans way to run Ethernet over coax" - but actually a different physical layer designed specifically for the purposes DirecTV intends to use it for.


You're doing a great service in that. Thank you for the time and effort you've put into your post and this thread. I've learned much from your post.


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## Sixto (Nov 18, 2005)

Been trying to figure out exactly what you guys are actually debating. 

The only question that seems important (to me) is whether it's financially justified for an all-Ethernet properly configured environment to be replaced/upgraded to all-DECA, and whether DECA-dongle is equivalent to all-Hx24.

Everything else is obvious. DECA is the future, and perfect for new installs and mixed environments.

RVU may be exclusive DECA (not sure if the remote nodes will have an Ethernet port).


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## BudShark (Aug 11, 2003)

Sixto said:


> Been trying to figure out exactly what you guys are actually debating.
> 
> The only question that seems important (to me) is whether it's financially justified for an all-Ethernet properly configured environment to be replaced/upgraded to all-DECA, and whether DECA-dongle is equivalent to all-Hx24.
> 
> ...


IMO - I would go all DECA. There is no advantage to using Ethernet other than pride and the time/effort/money put into installing it. And it will still be there and usable for Blu-Ray players, PS3s, Roku, PCs, etc. DECA is just a complimentary DirecTV network for MRV that is parallel with no existing wiring.

So - is it worth $150 ($99 + install) assuming no discounts? I'm with others. If it involves 3 or more receivers, and I don't have SWiM - Yes, I would think that it is regardless of availability of Ethernet. You *should* see performance improvement in MRV and you'll free up Coax for OTA if you want to existing double wired HRs. Plus you'd get 4 DECAs (1 for each receiver and 1 for the broadband connection). That seems like a good deal for me, and its remarkable how much cleaner a 1 cable solution is over a 3 cable solution (2 RG6 and 1 Cat5).

Beyond that - for those that have SWiM but not DECA, or only 2 receivers... its a choice.

Personally, when available in my world... I'm likely to go all out and upgrade my non-24s to HR24s (anyone want to buy an owned HR20 ). I'm not concerned about Whole Home, because 3 HR24s and an H24 all DECA connected is as good as Whole Home to me.


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## Doug Brott (Jul 12, 2006)

Sixto said:


> The only question that seems important (to me) is whether it's financially justified for an all-Ethernet properly configured environment to be replaced/upgraded to all-DECA, and whether DECA-dongle is equivalent to all-Hx24.


Agreed on this point .. I will say that DECA is optimized for MRV. Ethernet home networking will work and work well for well designed networks. If the quality of MRV with home networking meets your satisfaction, then it simply may not make sense to get DECA. If your satisfaction happens to decrease over time (perhaps due to changes in MRV), then you may later decide that DECA is worth the extra dollars for installation.


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## Doug Brott (Jul 12, 2006)

BudShark said:


> The reason for my thread, and the reason I am working to counter so many of the comments, is because there was a general feeling that DECA is less than Ethernet and that Ethernet was a better solution. Hopefully the thread opens some peoples eyes that DECA is not a "poor mans way to run Ethernet over coax" - but actually a different physical layer designed specifically for the purposes DirecTV intends to use it for.


BudShark,

Thanks. This is key. DECA is the better streaming solution. Ethernet still remains the better general purpose solution. Clearly you don't want to run your entire house on DECA.


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## Sixto (Nov 18, 2005)

BudShark said:


> IMO - I would go all DECA....


Interesting. 

First, DECA is great, is the perfect standard going forward, and perfect for new installs and mixed environments, especially those with no network connections or wireless.

But ...

For an existing environment with 7 receivers (all-H), all SWM, all hard-wired Cat5e to a single robust Switch ...

Question: there's a MRV performance advantage to removing all of the Ethernet connections and adding 7 DECA-dongles (plus 1 network-DECA) and moving the entire DirecTV communication off the Ethernet backbone?

Personally, I just can't imagine adding 8 new hardware items that need to be powered and could break. My plan has been to replace (over time) every receiver with an Hx24 receiver, and then when complete, switch to all-DECA. Clean.

I might change the plan based on this thread. 

Question-2: Finding it hard to understand how the MoCA benefits are provided for the DECA-dongle approach, where all traffic is through the Ethernet port, and I would expect that standard Ethernet/TCP/UDP protocols would be needed?. Hx24 could be pure MoCA.


----------



## Barry in Conyers (Jan 14, 2008)

Doug Brott said:


> Agreed on this point .. I will say that DECA is optimized for MRV. Ethernet home networking will work and work well for well designed networks. If the quality of MRV with home networking meets your satisfaction, then it simply may not make sense to get DECA. If your satisfaction happens to decrease over time (perhaps due to changes in MRV), then you may later decide that DECA is worth the extra dollars for installation.


Nicely stated! And I suspect / hope that the comment about "perhaps due to changes in MRV" *will* become relevant.


----------



## BudShark (Aug 11, 2003)

Sixto said:


> Interesting.
> 
> First, DECA is great, is the perfect standard going forward, and perfect for new installs and mixed environments, especially those with no network connections or wireless.
> 
> ...


You have an interesting decision to make 

It would be interesting to see. If I truly had to go through the steps you have to make the change - I might wait for Hx24 saturation. Obviously you have the knowledge and ability to biuld out a reliable ethernet infrastructure and support it (as others here can as well).

Since I'm already half-DECA, its an easier path for me. But, if I didn't - I would want to upgrade my core to eliminate a hop and build out more connections. I'd still be in trouble at the media cabinet since I would have 3 ethernet connected devices there and 1 Cat5e horizontal. So I guess what I'm saying is I'd go DECA before upgrading my Ethernet network. If your Ethernet network is already built out as you want/need it AND you have SWiM - well then its really just preference.


----------



## leww37334 (Sep 19, 2005)

Again the DECA solution is cheaper for Directv, but not necessarily for the consumer. 

It is also not the direction everyone else is headed. A large number of high end TV's, Blu Ray player's, etc now stream video from the internet. If you can put your Blu Ray player or your TV on the internet and get HD video from it, then why not your HR-xx? I believe ethernet (1 Gbps wireless) is the future, not the past. Also if you have your TV/ Blu Ray on the internet, you probably have an ethernet connection close by.

Integration with other technology (convergence) is more important than a stand alone, proprietary network that only talks to other Directv equipment. I think Directv may be headed in the wrong direction, but hey, it's new technology, so I have to try it.


----------



## BudShark (Aug 11, 2003)

leww37334 said:


> Again the DECA solution is cheaper for Directv, but not necessarily for the consumer.
> 
> It is also not the direction everyone else is headed. A large number of high end TV's, Blu Ray player's, etc now stream video from the internet. If you can put your Blu Ray player or your TV on the internet and get HD video from it, then why not your HR-xx? I believe ethernet (1 Gbps wireless) is the future, not the past. Also if you have your TV/ Blu Ray on the internet, you probably have an ethernet connection close by.
> 
> Integration with other technology (convergence) is more important than a stand alone, proprietary network that only talks to other Directv equipment. I think Directv may be headed in the wrong direction, but hey, it's new technology, so I have to try it.


While I don't disagree with your statements, I do think they aren't entirely accurate.

The "stand alone proprietary network" that DirecTV is using requires no new wiring, can coexist with the Ethernet network, and bridges to the Ethernet network so that the DirecTV receivers can/will be seen by other devices, do/can see other devices, and have access to the Internet. However, the primary reason for networking the DirecTV receivers (MRV) will not be dependent on that Ethernet network, can ride on a platform optimized for that purpose, and are still "converged" with everything else.

So I think what you want (convergence) is still there, while pulling the benefits of the MoCA solution for the particular receivers (some of which really don't need to be on a network with anything other than partner DirecTV receivers).


----------



## Sixto (Nov 18, 2005)

leww37334 said:


> Again the DECA solution is cheaper for Directv, but not necessarily for the consumer.
> 
> It is also not the direction everyone else is headed. A large number of high end TV's, Blu Ray player's, etc now stream video from the internet. If you can put your Blu Ray player or your TV on the internet and get HD video from it, then why not your HR-xx? I believe ethernet (1 Gbps wireless) is the future, not the past. Also if you have your TV/ Blu Ray on the internet, you probably have an ethernet connection close by.
> 
> Integration with other technology (convergence) is more important than a stand alone, proprietary network that only talks to other Directv equipment. I think Directv may be headed in the wrong direction, but hey, it's new technology, so I have to try it.


DirecTV has absolutely made the correct choice. It would be very difficult to debate against the importance of DECA.

DirecTV is using their existing Coax infrastructure, and for 95%+ of America, it's perfect and easy to install.

The only point I've been trying to understand is whether (today) DECA-dongle is "better" then a perfectly tuned all-Ethernet solution.

For the general population, DECA is perfect.


----------



## BudShark (Aug 11, 2003)

Sixto said:


> DirecTV has absolutely made the correct choice. It would be very difficult to debate against the importance of DECA.
> 
> DirecTV is using their existing Coax infrastructure, and for 95%+ of America, it's perfect and easy to install.
> 
> ...


Today - I doubt it assuming you have a currently working/acceptable Ethernet network. You might see a tad bit better trickplay performance. Otherwise, its unlikely you will see a difference today.


----------



## Sixto (Nov 18, 2005)

BudShark said:


> Today - I doubt it assuming you have a currently working/acceptable Ethernet network. You might see a tad bit better trickplay performance. Otherwise, its unlikely you will see a difference today.


Thank you sir.

And I will re-iterate ... DECA is great, and works very well from my own personal experience.


----------



## curt8403 (Dec 27, 2007)

Sixto said:


> Thank you sir.
> 
> And I will re-iterate ... DECA is great, and works very well from my own personal experience.


I think the bandwidth with Deca for inhouse use is way way higher than even the best standard Ethernet


----------



## veryoldschool (Dec 10, 2006)

curt8403 said:


> I think the bandwidth with Deca for inhouse use is way way higher than even the best standard Ethernet


"At best" this would be within the cloud, since each DECA has only a 100 Mb/s output/input.


----------



## Sixto (Nov 18, 2005)

curt8403 said:


> I think the bandwidth with Deca for inhouse use is way way higher than even the best standard Ethernet


DECA-dongle is 100mbps thru the Ethernet port.

The DECA-cloud (backbone) is 175mbps.

Hx24 DECA potentially could be better then 100mbps, assuming hardware and firmware capability. (don't know if there's an Ethernet bridge internally)


----------



## Steve (Aug 22, 2006)

veryoldschool said:


> "At best" this would be within the cloud, since each DECA has only a 100 Mb/s output/input.


Exactly.

And by the same token, you can use gigabit switches with ethernet and get a "backbone" capable of 2000 Mbps full-duplex, but the HR will be limited to 200 Mbps, full-duplex.


----------



## sorahl (Oct 24, 2002)

I agree that DECA is a great path for the average person out there (and the rest of my family). For me I can't see me putting out the extra money. I have 4 networks in my house. 1 Cat5e (my original) which I have put my Dtv Hr20x2 and HR21 on. These are the only devices on this network and I am very happy with the MRV functioning. It really has improved from the beginning of the beta implimentation.
I also have a Cat6 network that my pc's (6 of them) are on (plus my xbox 360 ( I know the device is only 100mb...). I stream WMC over this network and it also is awesome. I have a Wireless G network for our Wii, Zune, Iphones, DS's, Nokia, etc... I have a Wireless N network for my netbook.
I am not the typical consumer. so until DECA offers some features beyond QOS that I don't have via Ethernet I can see putting the money in to upgrading to DECA. 
Now if they want to provide whaever it is I need that's a different story! 

John


----------



## opfreak (May 8, 2008)

BudShark said:


> Actually not true.
> 
> MoCA was built within certain specifications to handle loops, splitters, and a variety of expected wiring conditions, including but not limited to RG59, RG6, RG6U, crimp connections, etc. In other words, its more tolerant of physical layer.
> 
> ...


So what your saying is that with proper optimization for Coax DTV and others were able to stream video over it? Amazing.

But somehow they are not able to provide that level of optimization over ethernet?

Again thats where the fud comes into play. Whatever protcall work was done for coax could have just as easly been done over ethernet.

Again, all streaming thats done reliable over ethernet proves that it can be done.

DTV just did it different, IMHO, nethier better nor worse, just different.

But you'll continue to tow the company line.


----------



## LameLefty (Sep 29, 2006)

opfreak said:


> So what your saying is that with proper optimization for Coax DTV and others were able to stream video over it? Amazing.
> 
> But somehow they are not able to provide that level of optimization over ethernet?
> 
> ...


"Protocal" not "protcall"
"Toe" not "tow"

That said, you are clearly missing the point.


----------



## evan_s (Mar 4, 2008)

opfreak said:


> So what your saying is that with proper optimization for Coax DTV and others were able to stream video over it? Amazing.
> 
> But somehow they are not able to provide that level of optimization over ethernet?
> 
> ...


The optimizations were not done at the protocol level. It is at the physical and data link layers.


----------



## Mike Bertelson (Jan 24, 2007)

opfreak said:


> So what your saying is that with proper optimization for Coax DTV and others were able to stream video over it? Amazing.
> 
> But somehow they are not able to provide that level of optimization over ethernet?
> 
> ...


It's more of a matter of optimizing for the networking scheme that DirecTV wants to support, and that's DECA. IOW, they may have chose not to optimize for Ethernet.

No mystery. 

Mike


----------



## BudShark (Aug 11, 2003)

opfreak said:


> So what your saying is that with proper optimization for Coax DTV and others were able to stream video over it? Amazing.
> 
> But somehow they are not able to provide that level of optimization over ethernet?
> 
> ...


The three posters above me get it. I have nothing to add.

Edit: I will add. You can't "optimize" Ethernet for anything. You can adjust your application to work with Ethernet, you can build QoS into your stack, you can depend on hardware and data link layer extensions to Ethernet - but you CAN'T optimize Ethernet for anything if you are DirecTV.

OR

You can use a system that was DESIGNED by someone other than DirecTV to be a multimedia distribution platform with the advantage of running on your existing network.

There is no magic here. Just your lack of understanding what the difference is between two networking technologies, what the advantages/disadvantages of each are, why one or the other makes sense in particular scenarios, and ultimately your insistince on my spreading of FUD - when only one of us has failed to back anything we've said with data, fact, architecture, and explained/outlined assumptions.

I am not always right, but I will always tell you why I believe what I do. You sir, are spreading FUD about DECA and about what I am saying. I have not spread a single piece of "FUD" in anything I have written.


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## Barry in Conyers (Jan 14, 2008)

LameLefty said:


> "Protocal" not "protcall"


Want to try again?


----------



## opfreak (May 8, 2008)

uverse whole house dvr uses ethernet without issue.


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## leww37334 (Sep 19, 2005)

BudShark said:


> You are absolutely correct. At the root of this is the fact that DirecTV is going to do whatever puts them in the best position to make money, and a solution that is more consistent and cheaper to support/install will do that.
> 
> The reason for my thread, and the reason I am working to counter so many of the comments, is because there was a general feeling that DECA is less than Ethernet and that Ethernet was a better solution. Hopefully the thread opens some peoples eyes that DECA is not a "poor mans way to run Ethernet over coax" - but actually a different physical layer designed specifically for the purposes DirecTV intends to use it for.


I guess I am getting more and more confused. I thought DECA stood for Directv Ethernet over Coax. If you use DECA adapters, isn't ethernet still involved, at least from the box to the dongle. If ethernet is such an incredibly poor medium for video, how do you avoid introducing all the ethernet problems from the dongles to the boxes? Also haven't you introduced all sorts of potential delays in the process of translating from TCP/IP to the MOCA protocols and back? I guess I just don't understand the protocol and I probably never will, since it is a proprietary standard.

And you are right Directv will do what is best for their bottom line, that is why we now pay over a thousand dollars a year for television.


----------



## Mike Bertelson (Jan 24, 2007)

opfreak said:


> uverse whole house dvr uses ethernet without issue.


So?

Mike


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## morphy (Jun 5, 2007)

Mommy and Daddy, please don't fight! 

My two cents on this discussion: its like our goal is to get a Ferrarri to hit a speed of 30 mph, and we're debating whether to use concrete or asphalt. Assuming that we are talking about a *proper* ethernet network and not any of the hackery going on in a lot of homes. A decent hardwired ethernet network will have 2-4ms of latency at the most. I can't scroll down a page on my DVR's UI without it taking 4 or 5 seconds. Yeah, I know its hyperbole, but my point is that at the rate that this equipment reponds to ANYTHING, I can't imagine the physical networked media to be a bottleneck assuming everything is as it should be.

I am more than confident that my ethernet switch could handle every Hx20 in my house bombarding it with packets as fast as possible. However, I've decided that I'm going DECA for two very important reasons:
1) I'm not on SWM yet, and its about time. 
2) I don't want "You're not on DECA" to start being the first excuse that a CSR uses when HBO gets mysteriously deleted from my account.


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## BattleScott (Aug 29, 2006)

opfreak said:


> uverse whole house dvr uses ethernet without issue.


Not in our area, they are connected by coax here.


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## Doug Brott (Jul 12, 2006)

morphy said:


> 2) I don't want "You're not on DECA" to start being the first excuse that a CSR uses when HBO gets mysteriously deleted from my account.


"You're not on DECA" will apply when you are having MRV issues .. beyond that, MAYBE, VOD, TV Apps or MediaShare issues, but that's not really clear to me at all.

In any event, what you've described above isn't even on the table.


----------



## Doug Brott (Jul 12, 2006)

opfreak said:


> uverse whole house dvr uses ethernet without issue.


DIRECTV is optimized over DECA but works over Ethernet as well.


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## BudShark (Aug 11, 2003)

opfreak said:


> uverse whole house dvr uses ethernet without issue.


!rolling !rolling !rolling :lol: :lol: :lol:

Ummm.... well.... !rolling... ummm... no they don't.

They use HomePNA (HPNA) which is... wait for it... closer to MoCA than Ethernet. Its a QoS focused physical layer designed to work over existing phone lines and coax lines. They are NOT using "ethernet" for their distribution. Sorry... try again :grin:


----------



## opfreak (May 8, 2008)

BudShark said:


> !rolling !rolling !rolling :lol: :lol: :lol:
> 
> Ummm.... well.... !rolling... ummm... no they don't.
> 
> They use HomePNA (HPNA) which is... wait for it... closer to MoCA than Ethernet. Its a QoS focused physical layer designed to work over existing phone lines and coax lines. They are NOT using "ethernet" for their distribution. Sorry... try again :grin:


Thanks for showing your ignorance.

Or when I had Uverse the installers must have been class A idiots and used my 5e cable to hook up my dvr and 2nd tv to the residental gateway.

Had no coax in the setup at all.

Amazingly had no issues


----------



## LameLefty (Sep 29, 2006)

Barry in Conyers said:


> Want to try again?


Every spelling flame on the internet must contain a typo. It's a law.


----------



## BudShark (Aug 11, 2003)

opfreak said:


> Thanks for showing your ignorance.
> 
> Or when I had Uverse the installers must have been class A idiots and used my 5e cable to hook up my dvr and 2nd tv to the residental gateway.
> 
> ...


Dude - seriously.

Cat5e does not equal "ethernet". Cat5e is just cabling. As is coaxial. On top of these cables is a media access method. That is what Ethernet is. That is what MoCA is. And that is what HPNA is. They are not cabling (in fact, Ethernet was originally developed for coaxial cabling).

What the uverse installer did, was use your Cat5e cabling to connect his HPNA motorolla set top box. He could also have used the coax cabling. His choice. But what HPNA is, is a method to send packets over cabling. Its an alternative to ethernet and MoCA. HPNA uses QoS mechanisms similar to what MoCA does, for the soul purpose of ensuring reliable video distribution. In fact, people with WHDVR and Uverse often note a degraded Internet connection speed when using Whole Home features - because the video is given higher priority.

I'm not ignorant. I live this and have for 20 years.


----------



## LameLefty (Sep 29, 2006)

BudShark said:


> Dude - seriously.
> 
> Cat5e does not equal "ethernet". Cat5e is just cabling. As is coaxial. On top of these cables is a media access method. That is what Ethernet is. That is what MoCA is. And that is what HPNA is. They are not cabling (in fact, Ethernet was originally developed for coaxial cabling).


In point of fact, the first network I had to maintain and expand was 10BaseT ethernet over coax.


----------



## opfreak (May 8, 2008)

BudShark said:


> Dude - seriously.
> 
> Cat5e does not equal "ethernet". Cat5e is just cabling. As is coaxial. On top of these cables is a media access method. That is what Ethernet is. That is what MoCA is. And that is what HPNA is. They are not cabling (in fact, Ethernet was originally developed for coaxial cabling).
> 
> ...


your the guy that said they connacted my house using coax.

Edit:

This isn't worth my time. You can keep telling yourself's that DECA is the 2nd coming and belive all you want. Your minds wont be changed.

Like I said before, from DTV's stand point having a single solution makes perfect sense. That however does not mean, Ethernet does not work.


----------



## BudShark (Aug 11, 2003)

BudShark said:


> !rolling !rolling !rolling :lol: :lol: :lol:
> 
> Ummm.... well.... !rolling... ummm... no they don't.
> 
> They use HomePNA (HPNA) which is... wait for it... closer to MoCA than Ethernet. Its a QoS focused physical layer designed to work over *existing phone lines and coax lines*. They are NOT using "ethernet" for their distribution. Sorry... try again :grin:





opfreak said:


> your the guy that said they connacted my house using coax.


You do realize phone lines are typically cat5e/cat3 correct? I never said they connected your house using coax... :shrug:


----------



## bobnielsen (Jun 29, 2006)

LameLefty said:


> In point of fact, the first network I had to maintain and expand was 10BaseT ethernet over coax.


That sounds familiar, but wasn't the coax version 10Base2? I set up some at work and even networked 3 computers in my house that way, circa 1992 or thereabouts. I still have a few 3Com ISA cards laying around.


----------



## LameLefty (Sep 29, 2006)

bobnielsen said:


> That sounds familiar, but wasn't the coax version 10Base2?


Oops, yes. Typo. 



> I still have a few 3Com ISA cards laying around.


I have one or two, plus a "Combo" card with both coax and RG connectors, and even a few terminators. Yuck. I hated that crap. :nono:


----------



## Thaedron (Jun 29, 2007)

bobnielsen said:


> That sounds familiar, but wasn't the coax version 10Base2? I set up some at work and even networked 3 computers in my house that way, circa 1992 or thereabouts. I still have a few 3Com ISA cards laying around.


Yes, it was 10Base2. The 2 being for 2-conductor. 10BaseT with T being for twisted pair. The data center I worked in had a coax backbone running through the computer room and used some coax between 10BaseT hubs in wiring closets. I remember the taps on the coax having to be spaced at particular intervals.

Now I feel old...


----------



## ffemtreed (Jan 30, 2008)

Thaedron said:


> Yes, it was 10Base2. The 2 being for 2-conductor. 10BaseT with T being for twisted pair. The data center I worked in had a coax backbone running through the computer room and used some coax between 10BaseT hubs in wiring closets. I remember the taps on the coax having to be spaced at particular intervals.
> 
> Now I feel old...


actually I thought the 2 stood for 2 hundred meter length. Just as 10base5 (thicknet) stood for 500 meter length.


----------



## Doug Brott (Jul 12, 2006)

opfreak said:


> This isn't worth my time. You can keep telling yourself's that DECA is the 2nd coming and belive all you want. Your minds wont be changed.


I don't think anyone here every said DECA is the second coming .. All that was stated was the DECA/MoCA is better for streaming video and trick plays than Ethernet. But it was also stated many times that Ethernet will work just fine.


----------



## Doug Brott (Jul 12, 2006)

ffemtreed said:


> actually I thought the 2 stood for 2 hundred meter length. Just as 10base5 (thicknet) stood for 500 meter length.


You sir .. are correct (by my recollection).


----------



## Thaedron (Jun 29, 2007)

Doug Brott said:


> You sir .. are correct (by my recollection).


I stand corrected. I always thought it was in reference to the # of conductors / type of cabling, much like the T stood for twisted pair... Learn something new every day.


----------



## Skyboss (Jan 22, 2004)

barryb said:


> Can we work on being a bit more respectful? Please?


Uh.. Sure.

DECA is not any better than what I have now and it would be a waste of time and money to require it. Sure, Joe Blow probably needs it because he doesn't even know what a network is, but not everyone is Joe Blow.

Thanks, and have a nice day. :goodjob:


----------



## hdtvfan0001 (Jul 28, 2004)

Skyboss said:


> Uh.. Sure.
> 
> *DECA is not any better than what I have now *and it would be a waste of time and money to require it. Sure, Joe Blow probably needs it because he doesn't even know what a network is, but not everyone is Joe Blow.
> 
> Thanks, and have a nice day. :goodjob:


I think its been pretty well established starting with the very first post that unless you have DECA already...that highlighted portion of your statment is not likely accurate for use within the current DirecTV MRV infrastructure.

Please enjoy your evening as well.


----------



## Skyboss (Jan 22, 2004)

ZPrime said:


> I'd love to see someone tell my QoS/Prioritized Ethernet switch at the office that it "Can't do that" because it's Ethernet and not DECA/MoCA. Our entire IP phone infrastructure would love to hear why it shouldn't be working because the switch shouldn't be able to do QoS.
> 
> While I don't disagree that DECA is a great solution for people w/o existing ethernet infrastructure, I do agree with opfreak -- it's verging on FUD to be yakking about how "OMG Ethernet isn't optimal, DECA is the win." Even if you do have daisychained switches, as long as you aren't trying to copy your DVD library from one PC to another across the single uplink while trying to stream a show, you won't have a problem. We're talking a few MPEG4 streams here. What kind of bandwidth do you think they take up on the satellite feed?
> 
> ...


What he said ^


----------



## Skyboss (Jan 22, 2004)

hdtvfan0001 said:


> I think its been pretty well established starting with the very first post that unless you have DECA already...that highlighted portion of your statment is not likely accurate for use within the current DirecTV MRV infrastructure.


Doubt it.


----------



## BudShark (Aug 11, 2003)

Skyboss said:


> Doubt it.


Then enlighten me (us). If I am so blatantly wrong (which is what you are saying) and the points to date are insufficient, then please give me a little more than "doubt it".


----------



## Skyboss (Jan 22, 2004)

BudShark said:


> You do realize phone lines are typically cat5e/cat3 correct? I never said they connected your house using coax... :shrug:


My house has fiber and CAT6... Everywhere. When the world catches up, DECA won't matter. Doesn't matter now.


----------



## LameLefty (Sep 29, 2006)

Skyboss said:


> My house has fiber and CAT6... Everywhere. When the world catches up, DECA won't matter. Doesn't matter now.


Here's advice from an engineer:

"Conclusory statement" ≠ "Data."

Thanks, and enjoy your weekend.


----------



## Doug Brott (Jul 12, 2006)

Skyboss said:


> My house has fiber and CAT6... Everywhere. When the world catches up, DECA won't matter. Doesn't matter now.


Ah I get it .. Since you spent money to install fiber and CAT6 in your house, there is absolutely no way that coax could be as good. Now it's clear.


----------



## Skyboss (Jan 22, 2004)

LameLefty said:


> Here's advice from an engineer:
> 
> "Conclusory statement" ≠ "Data."
> 
> Thanks, and enjoy your weekend.


I'm responding to his statement about cabling. Just pointing out... Not all home network infrastructure is equal. I for one have never had a problem with the existing MRV to include latency issues many talk about. Most likley because I'm not using a $100 router. Also likely because the DVRs are isolated from the rest of the network. Like I said, DECA is for the average Joe who probably can't un-clog a toilet let alone set up a basic network.


----------



## Skyboss (Jan 22, 2004)

Doug Brott said:


> Ah I get it .. Since you spent money to install fiber and CAT6 in your house, there is absolutely no way that coax could be as good. Now it's clear.


See above.


----------



## Doug Brott (Jul 12, 2006)

Skyboss said:


> Most likley because I'm not using a $100 router.


This is the Bingo! moment .. 

Not all home networks are created equal ..


----------



## harsh (Jun 15, 2003)

curt8403 said:


> I think the bandwidth with Deca for inhouse use is way way higher than even the best standard Ethernet


Define "best standard Ethernet".


----------



## harsh (Jun 15, 2003)

Doug Brott said:


> All that was stated was the DECA/MoCA is better for streaming video and trick plays than Ethernet. But it was also stated many times that Ethernet will work just fine.


Those two sentences would seem to be mutually exclusive at some level.

Some empirical data would certainly help people make informed (as opposed to impassioned) decisions.


----------



## Doug Brott (Jul 12, 2006)

harsh said:


> Those two sentences would seem to be mutually exclusive at some level.
> 
> Some empirical data would certainly help people make informed (as opposed to impassioned) decisions.


Then perhaps you should familiarize yourself with the first post in this thread.


----------



## David MacLeod (Jan 29, 2008)

Doug Brott said:


> Then perhaps you should familiarize yourself with the first post in this thread.


perhaps he should install and test it for us...


----------



## smiddy (Apr 5, 2006)

harsh said:


> Define "best standard Ethernet".


curt8403 can correct me if I am wrong, but I think you know what he meant; Ethernet specifically is 10 Mbps and 100 Mbps, 100 is usually characterised as Fast Ethernet, and I suspect he meant the 100 Mbps (this has been somewhat of a standard install for a few years, until recently where folks are using GigE). DECA is at least faster than 100 Mbps, which I suspect is what he was eluding to. YMMVT!


----------



## harsh (Jun 15, 2003)

Doug Brott said:


> Then perhaps you should familiarize yourself with the first post in this thread.


I did and that's why I asked the question. The first post makes references to the theory of DECA and how it should be better suited but it presents no empirical data (nor do the white papers referenced). While much can be learned about why MoCA feels justified in pounding its chest over what it has wrought, the real world numbers are lacking.

In reading about MoCA 1.1, I found that the "extra" bandwidth (over an above a shared 100Mbps) comes from "packet aggregation" (header reuse); something of little impact when full streaming frames are the data set.

http://www.videsignline.com/2068012...YGVZQE1GHPCKHWATMY32JVN?printableArticle=true

Here's a "where's the beef" paper about PQoS from a competing technology, HomePNA

http://homepnablog.typepad.com/my_weblog/2008/06/qos-part-1-home.html:

AT&T uses HomePNA 3.0 in its U-Verse product. Verizon uses MoCA.

The ITU is working on ITU-T G.hn that is supposed to deliver Gigabit over phone, coax and electrical wiring.

http://www.linkedin.com/answers/technology/wireless/TCH_WIR/305468-2056284

There are lots of technologies and each is mounting a campaign of rhetoric against the other. The time for hand-waving theories has passed now that DECA is available (if only to a precious few).


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## veryoldschool (Dec 10, 2006)

harsh said:


> The time for hand-waving theories has passed now that DECA is available (if only to a precious few).


And you'd need to use DirecTV to even be part of that "precious few", who will in fact be every subscriber within a few months, but "Oh yeah", you're not one, so why do you even care?


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## harsh (Jun 15, 2003)

smiddy said:


> curt8403 can correct me if I am wrong, but I think you know what he meant; Ethernet specifically is 10 Mbps and 100 Mbps, 100 is usually characterised as Fast Ethernet, and I suspect he meant the 100 Mbps (this has been somewhat of a standard install for a few years, until recently where folks are using GigE).


My home is Gigabit other than my router any my router has only my VOIP adapter and a connection to the Gigabit LAN. I've got about $120 invested in switches, cabling and termination hardware. What is "best" is different to different people and I have no illusions that my setup is ideal.

I also recognize and acknowledge that I've taken advantage of the fact that my lower floor has unfinished or suspended ceilings that have allowed me to easily run wire pretty much wherever I want. I've wall-fished both Cat5E and RG6 at the same time so labor is a wash.


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## harsh (Jun 15, 2003)

veryoldschool said:


> And you'd need to use DirecTV to even be part of that "precious few", who will in fact be every subscriber within a few months, but "Oh yeah", you're not one, so why do you even care?


Because many claims are being made based on non-evidentiary white papers and marketing rhetoric and that, in my mind, shouldn't be the driving force for choosing one technology over another.

Perhaps you should ask yourself why you don't care more about the truth being known.


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## Doug Brott (Jul 12, 2006)

harsh said:


> Because many claims are being made based on non-evidentiary white papers and marketing rhetoric and that, in my mind, shouldn't be the driving force for choosing one technology over another.
> 
> Perhaps you should ask yourself why you don't care more about the truth being known.


Are you suggesting that what is being mentioned is untrue?


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## LameLefty (Sep 29, 2006)

harsh said:


> Because many claims are being made based on non-evidentiary white papers and marketing rhetoric and that, in my mind, shouldn't be the driving force for choosing one technology over another.
> 
> Perhaps you should ask yourself why you don't care more about the truth being known.


What "truth" is that? Do please be specific and provide references. If you have any. Personal knowledge would be sufficient but of course, we know you have none with reference to DECA or mixed DECA/GigE networks, unlike many of those with whom you insist on arguing.

So again, specifics and references please.


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## veryoldschool (Dec 10, 2006)

harsh said:


> Because many claims are being made based on non-evidentiary white papers and marketing rhetoric and that, in my mind, shouldn't be the driving force for choosing one technology over another.
> 
> Perhaps you should ask yourself why you don't care more about the truth being known.


I'd say there is some good "facts" in this thread.
Since we can't pick and choose which form of networking, from your list, it simply comes down to using what we have without support, or using what DirecTV is offering with support. This is "the truth".
I don't need to restate the pros/cons of either, as they've been over and over here.
By the way: how's your dish system doing this?


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> And you'd need to use DirecTV to even be part of that "precious few", who will in fact be every subscriber within a few months, but "Oh yeah", you're not one, so why do you even care?


The dicussion about DECA vs. Ethernet needs fact, regardless of who the provider chooses to buy TV service from so I, for one, am glad that he does. It provides a good balance to alot the "Cloudy" (forgive the pun) information that is starting to saturate this and the other posts about the advantages of DECA over ethernet.

DECA/MOCA is obviously the correct platform for DirecTV and other providers to deploy their advanced services. But the reasons it is correct are the advantages gained by exploiting the existing COAX infrastructure that dominates the home landscape. The MoCA Alliance page is a clear testimonial to that concept. Attempts to further justify it based on some "perceived technical advantages" over ethernet are simply incorrect and are not needed.


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## Sixto (Nov 18, 2005)

harsh said:


> Because many claims are being made based on non-evidentiary white papers and marketing rhetoric and that, in my mind, shouldn't be the driving force for choosing one technology over another.
> 
> Perhaps you should ask yourself why you don't care more about the truth being known.


The net of all this is that DirecTV and Entropic created a cool technology that will work great for mainstream America. It utilizes the DirecTV SWM standard along with the existing Coax infrastructure.

While it may be fun to debate the intricate details of one technology over another, the net is that DECA is just fine for it's intended purpose, and may have some benefits now and in the future, over other methods.

For those with robust Ethernet networks, they'll be happy also, because everything will most likely work just fine.

In the future, the HMC with remote thin nodes (for RVU) may even require DECA, since at that point you'd be installing both new clients with the new server.

Best of both worlds, in the meantime, for everyone.


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> The dicussion about DECA vs. Ethernet needs fact, regardless of who the provider chooses to buy TV service from so I, for one, am glad that he does. It provides a good balance to alot the "Cloudy" (forgive the pun) information that is starting to saturate this and the other posts about the advantages of DECA over ethernet.
> 
> DECA/MOCA is obviously the correct platform for DirecTV and other providers to deploy their advanced services. But the reasons it is correct are the advantages gained by exploiting the existing COAX infrastructure that dominates the home landscape. The MoCA Alliance page is a clear testimonial to that concept. Attempts to further justify it based on some "percevied technical advantages" over ethernet are simply incorrect and are not needed.


 I'm not sure there is "incorrect" posts/statements here, but at the same time, I've not jumped on the bandwagon either.
Currently I'd say the "pluses" may be more forward looking than needed now. I suspect when the HMC30 system comes out, with many more streams, that this may become more effective.
RF in my thing and not networking, so take any of my thinking here with a grain of salt.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> I'm not sure there is "incorrect" posts/statements here, but at the same time, I've not jumped on the bandwagon either.
> Currently I'd say the "pluses" may be more forward looking than needed now. I suspect when the HMC30 system comes out, with many more streams, that this may become more effective.
> RF in my thing and not networking, so take any of my thinking here with a grain of salt.


Mainly I am referring to the statement that DECA/MOCA has a higher bandwidth than 100BaseT and that PQoS of MOCA makes it a better solution. On a simple switched ethernet network, QoS is of no concern as each device has it's own full duplex channel on which to communicate. Since that device can only be streaming a single stream, the bandwidth requirement is nowhere near that which would require QoS bandwidth reservations to assure delivery, the raw available bandwidth ensures it. In a MOCA/DECA environment the devices are all sharing the same transmission media, therefore the potential to reach the saturation point, and hence the need for guaranteed bandwidth for high-priority traffic is required.


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> Mainly I am referring to the statement that DECA/MOCA has a higher bandwidth than 100BaseT and that PQoS of MOCA makes it a better solution. On a simple switched ethernet network, QoS is of no concern as each device has it's own full duplex channel on which to communicate. Since that device can only be streaming a single stream, the bandwidth requirement is nowhere near that which would require QoS bandwidth reservations to assure delivery, the raw available bandwidth ensures it. In a MOCA/DECA environment the devices are all sharing the same transmission media, therefore the potential to reach the saturation point, and hence the need for guaranteed bandwidth for high-priority traffic is required.


I'll leave most of this to the network types, "but" "only be streaming a single stream" simply isn't the case, now, or in the future, which is where I believe this will have more impact.


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## harsh (Jun 15, 2003)

veryoldschool said:


> I'll leave most of this to the network types, "but" "only be streaming a single stream" simply isn't the case, now, or in the future, which is where I believe this will have more impact.


Relative to MRV and its current one-to-one, unidirectional relationship, "single stream" is an entirely accurate representation in a switched Ethernet environment. Any traffic from the client back to the server will travel along a different physical path.

The HMC is probably a little down-the-road and will likely be compared in an environment where Gigabit communications are the norm (including MoCA, if you believe their marketing materials).


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## veryoldschool (Dec 10, 2006)

harsh said:


> Relative to MRV and its current one-to-one, unidirectional relationship, "single stream" is an entirely accurate representation in a switched Ethernet environment. Any traffic from the client back to the server will travel along a different physical path.
> 
> The HMC is probably a little down-the-road and will likely be compared in an environment where Gigabit communications are the norm (including MoCA, if you believe their marketing materials).


So you've never told us how this is being done with your Dish system. So what's up?


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## harsh (Jun 15, 2003)

veryoldschool said:


> So you've never told us how this is being done with your Dish system. So what's up?


My home network is Gigabit Ethernet. I use a Slingbox for all of my MRV as well as remote viewing needs. It is widely available and it works with most provider's equipment should my priorities or interests change.

I could have probably gone with something less expensive, but remote viewing was a priority for me.


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## RAD (Aug 5, 2002)

harsh said:


> My home network is Gigabit Ethernet. I use a Slingbox for all of my MRV as well as remote viewing needs. It is widely available and it works with most provider's equipment should my priorities or interests change.
> 
> I could have probably gone with something less expensive, but remote viewing was a priority for me.


So you have a Slingbox on each of your DVR's and then also a Sling Catcher (which according to the Sling site only does SD) on each TV? Seems like an expensive setup.

I have only one Sling solo connected to one STB, but with MRV can then access all five HD DVR"s in my network.


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## harsh (Jun 15, 2003)

RAD said:


> So you have a Slingbox on each of your DVR's and then also a Sling Catcher (which according to the Sling site only does SD) on each TV?


In my case MRV is viewed entirely on computers (although there has been some promise of a future PS3 client). If I want to watch something on the Big TV, I watch it on the Big TV.

The Slingcatcher was software upgraded about a year ago to give "near HD" quality on a LAN. Still not lossless as ideally functioning streaming MRV should be, but good enough for smaller monitors in the the dining room, office and shop.


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## tcusta00 (Dec 31, 2007)

harsh said:


> In my case MRV is viewed entirely on computers (although there has been some promise of a future PS3 client). If I want to watch something on the Big TV, I watch it on the Big TV.
> 
> The Slingcatcher was software upgraded about a year ago to give "near HD" quality on a LAN. Still not lossless as ideally functioning streaming MRV should be, but good enough for smaller monitors in the the dining room, office and shop.


Sounds like you slapped some expensive hot pink lipstick on that pig. Good for you!!


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## Doug Brott (Jul 12, 2006)

harsh said:


> The HMC is probably a little down-the-road and will likely be compared in an environment where Gigabit communications are the norm (including MoCA, if you believe their marketing materials).


So the 90-95% of the Joe Six Packs without their DVRs networked will be upgraded to Gig Ethernet by the end of the year? That's a bit optimistic I think.


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## BudShark (Aug 11, 2003)

BattleScott said:


> Mainly I am referring to the statement that DECA/MOCA has a higher bandwidth than 100BaseT and that PQoS of MOCA makes it a better solution. On a simple switched ethernet network, QoS is of no concern as each device has it's own full duplex channel on which to communicate. Since that device can only be streaming a single stream, the bandwidth requirement is nowhere near that which would require QoS bandwidth reservations to assure delivery, the raw available bandwidth ensures it. In a MOCA/DECA environment the devices are all sharing the same transmission media, therefore the potential to reach the saturation point, and hence the need for guaranteed bandwidth for high-priority traffic is required.


Please show me a statement that says DECA/MoCA has higher bandwidth than 100BaseT - I've never said that.

In terms of PQoS - there's a reason AT&T, Verizon, and DirecTV all feel a QoS physical layer is important to the implementation of WHDVR. My reasoning for saying that DECA/MoCA is a better physical layer for WHDVR is based off the fact that it has a QoS at the physical layer, bandwidth scheduling and reservation. Both of those items can be minimized by bandwidth and switches in Ethernet - but not eliminated. Those issues are also why there are efforts to create QoS extensions in the physical layer for Ethernet - but they are so hardware specific and not as robust as MoCA, HPNA, or proposed G.hn that they aren't a good option.

In terms of "fact" - I'm honestly going to state that this forum is not the place to recreate the work that has been done. We have enough empirical evidence published already in first looks and CE tests that show DECA is extremely stable and in many cases better with even a single stream. In terms of the value of a QoS physical layer - a google search will provide you more evidence than anyone here.

If Ethernet is so widely sufficient in its pure unadulterated form - why do we have QoS extensions used primarily for voice and video services? I'm not "bashing" Ethernet. I'm stating a QoS physical layer is likely to have a large benefit when we get to WHDVR and multiple streams (again evidenced by the use of the two companies who already have implemented WHDVR, and clearly COULD have used Ethernet but didn't). I'm not sure DirecTV really should be getting beat up over this - they are just following FIOS and Uverse after all.


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## opfreak (May 8, 2008)

BudShark said:


> Please show me a statement that says DECA/MoCA has higher bandwidth than 100BaseT - I've never said that.
> 
> In terms of PQoS - there's a reason AT&T, Verizon, and DirecTV all feel a QoS physical layer is important to the implementation of WHDVR. My reasoning for saying that DECA/MoCA is a better physical layer for WHDVR is based off the fact that it has a QoS at the physical layer, bandwidth scheduling and reservation. Both of those items can be minimized by bandwidth and switches in Ethernet - but not eliminated. Those issues are also why there are efforts to create QoS extensions in the physical layer for Ethernet - but they are so hardware specific and not as robust as MoCA, HPNA, or proposed G.hn that they aren't a good option.
> 
> ...


I said I wouldn't but.

Every uverse manual I've seen refers to Hpna as only being used on the Coax or Cat3 (phoneline side), the other conections are all based on ethernet using ethernet standards.

Qos is a good thing. But QoS can be impemented and has been implemanted over ethernet. The biggest difference between the current ieee 801.p @ pQos, is that qPos reserves bandwidth. Why? Because your total bandwidth use the coax network is limited.

Again not a bash on Deca. But DTV could have nearly as easly specifed a standard ethernet router with Qos and stuck their sticker on it. Heck thats basically what ATT does.

All these companies are doing is attempting to use current wiring (ie coax) to do new things. Yes ethernet was original over coax. But we've moved past that. It seems to a point where things are coming full circle, and companies are again trying to run ethernet over coax.

Some here are honest about what DTV is doing: being lazy. Coax already exists in most houses. And if its the wrong grade, its still easier to replace then creating a new ethernet cable. They are about simplification. Deca gives them that. Nothing more, nothing less.


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## Sixto (Nov 18, 2005)

opfreak said:


> I said I wouldn't but ...
> 
> Some here are honest about what DTV is doing: being lazy. Coax already exists in most houses. And if its the wrong grade, its still easier to replace then creating a new ethernet cable. They are about simplification. Deca gives them that. Nothing more, nothing less.


Not sure what the debate is all about.

It made perfect sense to work with Entropic and develop a nice solution based on the MoCA standard over the existing SWM/Coax infrastructure.

Anything else would have been much more of a challenge to roll-out to mainstream America.

Debating whether the same could have been done over Ethernet seems meaningless. Not everyone has a home Ethernet network, while the DirecTV standard is for everyone to have SWM/Coax eventually, and all new installs are SWM/Coax.

And the good news is that Ethernet works fine as well, for those that already made that investment. Yes, there may be some slight performance advantage to DECA today, and possibly a more significant advantage in the future (when multiple streams originate from a single receiver), but that's up to those with Ethernet networking to decide when/if they ever want to convert.

I guess maybe you could debate that DirecTV should optimize for both environments, but that's probably not good money spent in this economy.


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## BudShark (Aug 11, 2003)

opfreak said:


> *Some here are honest about what DTV is doing: being lazy.* Coax already exists in most houses. And if its the wrong grade, its still easier to replace then creating a new ethernet cable. They are about simplification. Deca gives them that. Nothing more, nothing less.


That has to be the most clueless comment I have read.

DirecTV is lazy because they use the wiring they HAVE to put in place for your system to work, rather, than as you suggested above, they mandate a specific class or type of router (heh, maybe they should provide it like Uverse too?) and ensure the quality of a whole other set of wiring that is currently NOT needed for the service they provide?

You call this being lazy vs. using a valid, working, QoS based method that uses their existing wiring with no further requirements?

Why the hell would DirecTV get involved in your Internet service (by potentially asking you to change or providing you a router) and forcing a second wiring solution where one wasn't needed? How does that make ANY sense at all?

What engineer/network architect do you know that would create a more complex setup just so he could use Ethernet when he has a simpler solution with less cabling that meets every one of his needs at his hands?

And you call this being lazy?


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## Doug Brott (Jul 12, 2006)

I was confused with the word 'lazy' as well .. I would have chosen 'prudent' instead.


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## Sharkie_Fan (Sep 26, 2006)

opfreak said:


> Some here are honest about what DTV is doing: being lazy. Coax already exists in most houses. And if its the wrong grade, its still easier to replace then creating a new ethernet cable. They are about simplification. Deca gives them that. Nothing more, nothing less.


I've been reading this thread since it started with great interest. Admittedly, the technical stuff goes WAY over my head (and when I say way over my head, I'm talking the same way that I could say the sun is over my head. A really long pole with a net and I still couldn't catch the stuff some of you are talking about!)

BUT... I wouldn't call the decision to move to DECA *lazy*. Whether the premises in post #1 are right on or right out of left field is secondary, in my mind, to the fact that DECA provides a solution that an installer can easily set up for "Joe Blow" without a bunch of extra work.

To me, the bottom line is it works "the same", at the very least. IF the assesments made in post #1 are correct, then down the road, DECA has the _potential_ to offer superior performance. Even if it doesn't live up to that potential, it works just as well as an ethernet set up, without a bunch of extra stuff having to be done. An extra step here or there during a "standard install", and the customer has a working MRV environment.

Although I'm probably among the least "techie" people here, I'm an uber-nerd compared to many of my friends, family, and coworkers. Many of them have a single computer, with no network infrastructure whatsoever.... but they have a TV in every room. Some of them even still use VCRs so they can tape something in one room and watch it in another. 

So... lazy isn't the characterization I would use. Even if you're 100% right and they chose DECA over Ethernet because it's easier to install/maintain... I wouldn't call it lazy.


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## P Smith (Jul 25, 2002)

Don't discard one of driving force of such invention - increasing revenue by using proprietary technologies.


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## DogLover (Mar 19, 2007)

P Smith said:


> Don't discard one of driving force of such invention - increasing revenue by using proprietary technologies.


While I'm sure DirecTV will do their best to recover the costs of using this technology, and maybe make a little profit in the proccess. However, I can't imagine that the return on investment would be enough to be a "driving force" in its invention.


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## smiddy (Apr 5, 2006)

harsh said:


> My home is Gigabit other than my router any my router has only my VOIP adapter and a connection to the Gigabit LAN. I've got about $120 invested in switches, cabling and termination hardware. What is "best" is different to different people and I have no illusions that my setup is ideal.
> 
> I also recognize and acknowledge that I've taken advantage of the fact that my lower floor has unfinished or suspended ceilings that have allowed me to easily run wire pretty much wherever I want. I've wall-fished both Cat5E and RG6 at the same time so labor is a wash.


If I get your drift, I see what you mean (does tha make sense? ). GigE is fairly inexpensive these days. Why doesn't DirecTV just put a GigE RJ-45 into their box instead? Unfortunately I don't believe we know all the trade offs that DirecTV is cycling through, however I would suspect, since GigE is a bit overkill for streaming anything, and a little better than Fast Ethernet works pretty well, that DECA was chosen. Also, DECA provides a layer of seperation form "the rest of the network" so that interference from high capacity bandwidth items won't collide with their MRV (this is a guess on my part, but seems doable/excuteable logically).


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## smiddy (Apr 5, 2006)

opfreak said:


> [delete]
> Some here are honest about what DTV is doing: being lazy. Coax already exists in most houses. And if its the wrong grade, its still easier to replace then creating a new ethernet cable. They are about simplification. Deca gives them that. Nothing more, nothing less.


Lazy? Yikes, :scratchin I see their decision as meritful and worhty of bringing costs down on both sides (consumer and provider), it provides options, it was well thought out looking at the trade offs on a lot of levels, this implementation of ethernet over a coax is not indicative of past implementations at all, it is however consistant with DirecTV's use of chanellized signals over coax, to provide more capabilties, from teh satellite to the consumer. It simplifies, perhaps this is why you say lazy. Hey, E=MC^2 and F=MA are simplistic equations, but a lot of thought went into finding them. While DirecTV's implementation of DECA doesn't rank as high as those equations, I submit they put ample engineering thought into making DECA a reality.


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## P Smith (Jul 25, 2002)

DogLover said:


> While I'm sure DirecTV will do their best to recover the costs of using this technology, and maybe make a little profit in the proccess. However, I can't imagine that the return on investment would be enough to be a "driving force" in its invention.


I've seen that in real life, and more - just using some registered logo on certified product would give the company pretty hefty amount.


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## Kansas Zephyr (Jun 30, 2007)

There are too many posts on this subject to back through each one. So, my apologies if this has been asked before.

I've seen 500-600MHz...and 550MHz listed for the DECA.

Has anyone looked at DECA with spectrum analyzer, and knows the x-yMHz bandwidth actually used?

Thanks.


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## veryoldschool (Dec 10, 2006)

Kansas Zephyr said:


> There are too many posts on this subject to back through each one. So, my apologies if this has been asked before.
> 
> I've seen 500-600MHz...and 550MHz listed for the DECA.
> 
> ...


No, but the band is 525 to 575 MHz.


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## leww37334 (Sep 19, 2005)

Smiddy, here's another formula for you f <= 2B, Nyquist rate. If the bandwidth is 50 Mhz as VOS said then the pulse rate can be at most 100 mbps.


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## Mike Bertelson (Jan 24, 2007)

opfreak said:


> <snip>
> Again not a bash on Deca. But DTV could have nearly as easly specifed a standard ethernet router with Qos and stuck their sticker on it. Heck thats basically what ATT does.
> 
> <snip>
> ...


Lazy? And those that think that are the only ones being honest about DirecTV?

Well, I believe I'm being honest when I say I think this is a good idea. Why the heck would it be better to stick their name on another piece of hardware when there's no need for it? They have toi use the coax so why create another level of hardware and wiring when they don't have to?

It's not being lazy, it's being smart. They can network all their receivers without having to use a separate router, without having to use additional cable, and all without having to install anything more than they do now. Is it being lazy when you create new hardware/firmware from scratch instead of using off the shelf components? It seems to me to lazy to use off the shelf components that you can't provide tech support for just so it saves you money... that would be lazy. 

Mike


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## Kansas Zephyr (Jun 30, 2007)

veryoldschool said:


> No, but the band is 525 to 575 MHz.


Thanks!


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## gr8ful (May 12, 2009)

This reminds me of IBM's token ring, which theoretically would handle heavy network loads better than Ethernet, until studies showed that to be false. Then all the token ring shops had to toss that expensive token ring equipment for much cheaper Ethernet hardware,

Are you really suggesting your 100 mbit connection, with the associated overhead described in the slides, will provide superior performance to my 1,000 mbit network? 

Once you run a comparison, then I'll be more likely to believe. But the lack of such comparisons makes the slides look good in theory, but ultimately, not compelling.

In fact it would believe it there are no such comparisons. So where are they?


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## gr8ful (May 12, 2009)

BudShark said:


> 4) *Can I use my existing Ethernet network for MRV after the beta period?*
> A: The current response through the moderators on DBSTalk is, yes. You will have to pay the monthly MRV fee and you will receive no technical support for MRV from DirecTV.


Which is the same with every device we connect to our local network, right? I got no support for my TV's, Receiver's, Google TV, Cell Phones, iPods, Laptops, PS3, Wii, my AP unit, etc. My ISP ensures I get a connection into the house, and then it's up to me, and it's usually trivial to set up and maintain.


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## inkahauts (Nov 13, 2006)

Mrv is a core feature at this point. DIRECTV has to support it. Deca let's them. Your own personal network does not. Deca just works for DIRECTV and Whole Home Service. No debates if ands or buts. It may or may not work with a persons network well. 

Deca does exactly what it's designed to do which is what 99.99 % of dtv customers need. 

So yes moca is better for Whole Home Service than your personal network from DIRECTV standpoint because its specialized for working just on their environment and it isolates the Whole Home Service traffic as much as possible from everything else you may have on your network. 

There doesn't need to be any other kind of comparison because it doesn't matter. 

And by the way you do t pay a monthly fee to your tv or player for Whole Home Service. You do for DIRECTV so there is an expectation to keep it working from their end. 


Sent from my iPhone using DBSTalk mobile app


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## The Merg (Jun 24, 2007)

gr8ful said:


> Which is the same with every device we connect to our local network, right? I got no support for my TV's, Receiver's, Google TV, Cell Phones, iPods, Laptops, PS3, Wii, my AP unit, etc. My ISP ensures I get a connection into the house, and then it's up to me, and it's usually trivial to set up and maintain.


However, some people would be under the impression that when something with Whole Home is not working, access to the Internet for VOD has issues, or the iPad app is not working correctly, that DirecTV should come out and fix the issue. Due to all the troubleshooting that would be required with receivers hooked up via Ethernet and other considerations, DirecTV will come out, but only if the customer is using a supported DECA setup. The tech can easily disconnect the receivers from the home network and then diagnose if the issue has to do with the receivers or the home network at that point.

BTW, you realize this thread has been dead for 3-1/2 years, right?

- Merg


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## veryoldschool (Dec 10, 2006)

Given the age of this thread and the uselessness of rehashing this, I'm closing it.

Should anyone feel they need to go over this again, either PM me or start a new thread.


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