# DECA for PC?



## mikeny (Aug 21, 2006)

Has anyone tried to hook up their PC to a powered DECA? Would that work for MRV or even the internet?


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## veryoldschool (Dec 10, 2006)

mikeny said:


> Has anyone tried to hook up their PC to a powered DECA? Would that work for MRV or even the internet?


In a way, it's done all the time. Since you need to have a broadband connection to your router [to post here :lol:] you can use your home network for the PC and use the DECA + PI to connect your receivers to your home network.
The DECA structure isn't idea for PC only traffic.


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## mikeny (Aug 21, 2006)

veryoldschool said:


> In a way, it's done all the time. Since you need to have a broadband connection to your router [to post here :lol:] you can use your home network for the PC and use the DECA + PI to connect your receivers to your home network.
> The DECA structure isn't idea for PC only traffic.


Yeah, I know you tried it and tested it for DirecTV2PC or something.


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## veryoldschool (Dec 10, 2006)

mikeny said:


> Yeah, I know you tried it and tested it for DirecTV2PC or something.


Streaming it works great for, so DirecTV2PC works fine.
What it might not do well is bridge a PC to your home network.


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## harsh (Jun 15, 2003)

The answer may lie in a second computer Ethernet connection to the DECA cloud -- perhaps even sharing its Internet connection to the DVRs. In theory, this could keep the non-MRV computer traffic off the cloud.


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## veryoldschool (Dec 10, 2006)

harsh said:


> The answer may lie in a second computer Ethernet connection to the DECA cloud -- perhaps even sharing its Internet connection to the DVRs. In theory, this could keep the non-MRV computer traffic off the cloud.


Maybe not "off the cloud" but have it receive a very low priority on/in the cloud.


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## Grentz (Jan 10, 2007)

DECA is not some magical thing, it is still just ethernet protocols. So to answer, yes, it does work fine for connecting a computer.

The thing is that it has been tuned to work best with streaming traffic (something that can be done on wired ethernet connections as well with certain hardware). So I would not recommend it for connecting your computers up.


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## kyledr04 (May 15, 2010)

Grentz said:


> DECA is not some magical thing, it is still just ethernet protocols. So to answer, yes, it does work fine for connecting a computer.
> 
> The thing is that it has been tuned to work best with streaming traffic (something that can be done on wired ethernet connections as well with certain hardware). So I would not recommend it for connecting your computers up.


What about connecting the DECA cloud to a PC primarily used for streaming online content? Would it be more efficient that a wireless connection to that same PC?


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## 2dogz (Jun 14, 2008)

kyledr04 said:


> What about connecting the DECA cloud to a PC primarily used for streaming online content? Would it be more efficient that a wireless connection to that same PC?


Anything is better than wireless.


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## harsh (Jun 15, 2003)

veryoldschool said:


> Maybe not "off the cloud" but have it receive a very low priority on/in the cloud.


I was thinking in terms of keeping computerly things off the cloud altogether. Similar to putting in a router to insulate the DECA cloud but still allowing the computer to be on the cloud. Using a router and dual-homing the computer would do the same thing but cost more.


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## harsh (Jun 15, 2003)

kyledr04 said:


> Would it be more efficient that a wireless connection to that same PC?


The goal should be to keep non-MRV traffic off the cloud, not to go out of your way to incorporate it.


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## Steve (Aug 22, 2006)

FWiW Verizon FiOS TV/Internet installs are all MoCA/coax, even to PC's, so everything is in the same cloud. Haven't heard or read about any LAN performance issues from folks set up that way.


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## veryoldschool (Dec 10, 2006)

Steve said:


> FWiW Verizon FiOS TV/Internet installs are all MoCA/coax, even to PC's, so everything is in the same cloud. Haven't heard or read about any LAN performance issues from folks set up that way.


Someone here got DECA and then tested the throughput with some app and noticed it wasn't as fast as what they were using before. Not sure if it was wireless, powerline, or what.
I have tested my DECA @ above 250 Mb/s between them.


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## houskamp (Sep 14, 2006)

does it work? yes.. is it any better? not that I noticed in the breif time I had it connected (was to verify my deca connection)..


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## hitokage (Jan 19, 2010)

Grentz said:


> DECA is not some magical thing, it is still just ethernet protocols. So to answer, yes, it does work fine for connecting a computer.


+1

DECA adapters are network bridges, and except for the frequencies they use they are exactly the same as MoCAs.



Grentz said:


> The thing is that it has been tuned to work best with streaming traffic


I don't believe they actually did anything like this though. Deviating too much from the MoCA designs would increase their costs too much - it works well enough on wired ethernet, making it a few milliseconds faster isn't going to be cheap. Besides, if it's only supposed to be used for MRV and DoD (no not the other DoD) it would have nothing to prioritize traffic over. The boxes are also using standard TCP/IP to talk to each other, so the best they could do is tweak the protocol stack on the boxes - which as far anyone here can determine was part of what they were doing before the official release.


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## HoTat2 (Nov 16, 2005)

Steve said:


> FWiW Verizon FiOS TV/Internet installs are all MoCA/coax, even to PC's, so everything is in the same cloud. Haven't heard or read about any LAN performance issues from folks set up that way.


Are you sure?

I thought Verizon FiOS used a similar scheme of separating the MRV TV traffic from the home computer network by placing the DVRs/STBs on the coaxial cable portion of the network which communicate with each other over MoCA whereas the computers remain isolated on the ethernet portion.

The two clouds are then connected to each other with a "coax MoCA enabled" router (still produced by Actiontec?) whenever to two need to cross over.


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## Steve (Aug 22, 2006)

HoTat2 said:


> Are you sure?
> 
> I thought Verizon FiOS used a similar scheme of separating the MRV TV traffic from the home computer network by placing the DVRs/STBs on the coaxial cable portion of the network which communicate with each other over MoCA whereas the computers remain isolated on the ethernet portion.
> 
> The two clouds are then connected to each other with a "coax MoCA enabled" router (still produced by Actiontec?) whenever to two need to cross over.


Not in the four installs I've seen (mom, sister, son at two different homes). They run coax everywhere and either connect a STB, DVR, Actiontec router (w. MoCA), or a MoCA to CAT5 adapter as needed for that location. Maybe they're taking a shortcut? They ran no CAT5 in those installs, tho.

When I had FiOS internet installed back in 2006, they ran a CAT5 from the ONT to my attic because, at that time, they weren't provisioning TV yet in my area and their routers were standard D-Link's.


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## HoTat2 (Nov 16, 2005)

Steve said:


> Not in the four installs I've seen (mom, sister, son at two different homes). They run coax everywhere and either connect a STB, DVR, Actiontec router (w. MoCA), or a MoCA to CAT5 adapter as needed for that location. Maybe they're taking a shortcut? They ran no CAT5 in those installs, tho.
> 
> When I had FiOS internet installed back in 2006, they ran a CAT5 from the ONT to my attic because, at that time, they weren't provisioning TV yet in my area and their routers were standard D-Link's.


OK;

Was referencing the info. from here illustrating the separate clouds for a FiOS install;

http://www.hanselman.com/blog/VerizonFIOSTVReviewAndPhotoGallery.aspx

http://www.hanselman.com/blog/LeavingComcastForVerizonFiosUpgradingTheHomeNetworkToFiberOptic.aspx

Though it is from early 2008 and thus a bit dated I guess.


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## Steve (Aug 22, 2006)

HoTat2 said:


> OK;
> 
> Was referencing the info. from here illustrating the separate clouds for a FiOS install;
> 
> http://www.hanselman.com/blog/VerizonFIOSTVReviewAndPhotoGallery.aspx


In the first example, looks to me like the author already had a CAT5 Lan in place prior to the TV service install, so no need to re-invent the wheel:

_"Since I had Verizon FIOS Internet already, hooking up the TV was easy for the installer. He used my existing Coax spliter and split the wire before the router. So, the coax comes in from the outside then splits and heads into all the rooms in the house, with one of the downstream cables going into the Verizon Internet Router's Coax connector. From there the router speaks TCP/IP over RJ-45 and supplies the house, but it also can hand out IP addresses over Coax to the DVR (Digital Video Recorders) that you'll receive with the FIOS TV Package."_

So the separation probably wasn't by design, but simply working with what was already in place. That's what would happen in my home, e.g., if I switched to FiOS TV now. I'd want to re-use all my existing Cat5 connections and cabling, and simply connect them to the same router the TV is coming in on.



> http://www.hanselman.com/blog/LeavingComcastForVerizonFiosUpgradingTheHomeNetworkToFiberOptic.aspx


In this set-up, there is no TV cloud... looks like they only switched to FiOS for internet. While all LAN traffic inside the home is connected to a hub (bad idea, IMO. Hopefully they meant to say "switch"), you'll see that any WAN traffic goes through two conversions... first Cat5 to MoCA, via the Verizon router, and then MoCA to fiber, via the ONT.


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## Grentz (Jan 10, 2007)

veryoldschool said:


> Someone here got DECA and then tested the throughput with some app and noticed it wasn't as fast as what they were using before. Not sure if it was wireless, powerline, or what.
> I have tested my DECA @ above 250 Mb/s between them.


You might be referring to me, I dunno. When I did testing, I found that DECA was much better in throughput and simultaneous connections than wireless or powerline. It also was *better at simultaneous connections* than standard 10/100. It of course could not hold a candle to gigabit.

For the DirecTV receivers, which only have 10/100 interfaces, the aspect of multiple streams is important as that means that many receivers can be streaming to each other and not slow the cloud down significantly. The speed itself is not THAT important considering the receivers are only 10/100. Keep in mind the link between the DECA and receiver is just a standard 10/100 ethernet connection, so DECA cannot improve on that.



hitokage said:


> I don't believe they actually did anything like this though. Deviating too much from the MoCA designs would increase their costs too much - it works well enough on wired ethernet, making it a few milliseconds faster isn't going to be cheap. Besides, if it's only supposed to be used for MRV and DoD (no not the other DoD) it would have nothing to prioritize traffic over. The boxes are also using standard TCP/IP to talk to each other, so the best they could do is tweak the protocol stack on the boxes - which as far anyone here can determine was part of what they were doing before the official release.


Interfaces can have QoS and optimizations for certain types of traffic.

In my testing I found that DECA is very good at multiple streams passing through it at once, though not max speeds. For example, it could have 4 streams going at a certain speed, but that cap would still be fairly similar with only 1 stream going through it. There was a point of saturation with too many streams where all the streams suffered in throughput, but it was fairly high as I remember.

Simultaneous streams, IMO, is the main advantage to DECA as far as the quality of the link between receivers. If you have an optimized and properly setup ethernet network, there will be no difference. But most homes do not have that and it is too hard to support all the different configurations. Thus DECA is the best answer for everyone (DirecTV and Customers).


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## veryoldschool (Dec 10, 2006)

Grentz said:


> You might be referring to me, I dunno. When I did testing, I found that DECA was much better in throughput and simultaneous connections than wireless or powerline. It also was *better at simultaneous connections* than standard 10/100. It of course could not hold a candle to gigabit.
> 
> For the DirecTV receivers, which only have 10/100 interfaces, the aspect of multiple streams is important as that means that many receivers can be streaming to each other and not slow the cloud down significantly. The speed itself is not THAT important considering the receivers are only 10/100. Keep in mind the link between the DECA and receiver is just a standard 10/100 ethernet connection, so DECA cannot improve on that.


It can when the DECA is internal.


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## hitokage (Jan 19, 2010)

Initial FIOS installs used one CAT5 (or some approved variant) drop from the ONT because they didn't have the MoCA stuff ready yet.

Yes, interfaces can support QoS, but in this case I'm sure the DECAs don't. The reason for better performance over a _basic_ ethernet network is probably from the reduced complexity of a DECA versus an ethernet switch. The ethernet switch may be good for 100Mbs between ports, but there is an internal bandwidth limit that may be showing up more readily on cheaper switches.


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## Steve (Aug 22, 2006)

veryoldschool said:


> It can when the DECA is internal.


I was actually wondering about that. I wanted to test it, but wasn't sure how!


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## harsh (Jun 15, 2003)

hitokage said:


> Yes, interfaces can support QoS, but in this case I'm sure the DECAs don't.


MoCA 1.1 (DECA) has a version of QoS (biased towards streaming packets) as well as some shorthand header compression that takes advantage of the limited number of clients supported.


> The ethernet switch may be good for 100Mbs between ports, but there is an internal bandwidth limit that may be showing up more readily on cheaper switches.


Even the cheap switches have enough fabric for all ports at once (an n port gigabit switch typically has n gigabits of bandwidth.


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