# DECA for computer network



## ewing453 (Oct 22, 2008)

Has anyone tried using spare DECA's to create a computer network over Coax? This would be seperate from MRV network. I have some coax feeds going to a location I would like to locate a hardwired ethernet connection.

1) What are the speeds on the DECA?
2) What is the distance limitation of the cable?


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## dmurphy (Sep 28, 2006)

ewing453 said:


> Has anyone tried using spare DECA's to create a computer network over Coax? This would be seperate from MRV network. I have some coax feeds going to a location I would like to locate a hardwired ethernet connection.
> 
> What are the speeds on the DECA?


175mbit.

The DECAs are MoCA 1.1 compliant.

http://en.wikipedia.org/wiki/Multimedia_over_Coax_Alliance


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## veryoldschool (Dec 10, 2006)

ewing453 said:


> What are the speeds on the DECA?


While the coax has a higher rate/speed, the ethernet port is 100 Mb/s.


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## dmurphy (Sep 28, 2006)

veryoldschool said:


> While the coax has a higher rate/speed, the ethernet port is 100 Mb/s.


True enough - I was thinking more of the line rate of the entire 'cloud', rather than per-port speeds... my apologies for the confusion


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## veryoldschool (Dec 10, 2006)

dmurphy said:


> True enough - I was thinking more of the line rate of the entire 'cloud', rather than per-port speeds... my apologies for the confusion


I'm not sure your cloud rate a correct either since the 24s have some coax networking tests that can show a "mesh rate" of 250+.


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## JosephB (Nov 14, 2005)

Something to think about for this project: What else is on that coax? Are there DirecTV receivers on that coax or cable/OTA? DirecTV's DECAs are different from standard MoCA by shifting the frequencies into the OTA/Cable TV range. So, if you're sending OTA or cable down that cable, you will want to buy just standard MoCA gear. If you're sending DirecTV down that cable, you'll want to buy DECAs


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## dmurphy (Sep 28, 2006)

veryoldschool said:


> I'm not sure your cloud rate a correct either since the 24s have some coax networking tests that can show a "mesh rate" of 250+.


I'm just quoting the rate of the MoCA 1.1 specs ... If we are getting significantly greater performance (as it appears we are), then that's even more awesome


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## ewing453 (Oct 22, 2008)

JosephB said:


> Something to think about for this project: What else is on that coax?


Nothing else, totally seperate coax.

Anybody find the distance limitations? I saw one spec that said over 300 meters.


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## veryoldschool (Dec 10, 2006)

ewing453 said:


> Nothing else, totally seperate coax.
> 
> Anybody find the distance limitations? I saw one spec that said over 300 meters.


With a single coax end to end, 300 meters of RG6 will work, with a slight amount of loss to spare.


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## dsw2112 (Jun 13, 2009)

I did this for my neighbor and he's thrilled with it (single coax with DECA at each end.) Just as an FYI if using DECA dongles you'll need to have a PI for each one.


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## JosephB (Nov 14, 2005)

You may want to look at standard MoCA equipment, it may be cheaper and won't require PIs.


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## dsw2112 (Jun 13, 2009)

JosephB said:


> You may want to look at standard MoCA equipment, it may be cheaper and won't require PIs.


My neighbor did his setup for $30 thanks to Ebay (2 PI's and 2 DECA dongles.) I don't know what the "regular" MOCA stuff goes for nowadays, but DECA equipment can be found extremely cheap...


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## bobnielsen (Jun 29, 2006)

JosephB said:


> You may want to look at standard MoCA equipment, it may be cheaper and won't require PIs.


I haven't checked recently, but a year or so ago I paid nearly $150 for a pair of MoCA adapters with power supplies. I used these for MRV over my OTA cables before getting DECA.


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## dhickman (Apr 23, 2010)

ewing453 said:


> Has anyone tried using spare DECA's to create a computer network over Coax? This would be seperate from MRV network. I have some coax feeds going to a location I would like to locate a hardwired ethernet connection.
> 
> 1) What are the speeds on the DECA?
> 2) What is the distance limitation of the cable?


I think 175 mbit and 300feet.

Keep in mind that this type of network will have collision issues and you may never see anything close to the 100bit max of the feecee computer.

But to hard wire a remote room/computer this should be acceptable to all but people like me who will max the gige in my house.

dhh


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## veryoldschool (Dec 10, 2006)

dhickman said:


> I think 175 mbit and 300feet.
> 
> Keep in mind that this type of network will have collision issues and you may never see anything close to the 100bit max of the feecee computer.
> 
> ...



Not sure why you haven't read the earlier posts but:
The bit-rate can be higher within the coax, while being limited by the DECA output being 100 Mb/s.
300 METERS not feet is well within the RF range in RG-6.
"Collisions" in a modulated RF signal?


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## djrobx (Jan 27, 2009)

I've found that DECAs perform very well with PCs. I can transfer files and get 90% utilization out of the 100mbps ethernet link, about the same as I get from a plain 100mbps switch. There's a little bit of additional latency (~4ms), but the performance beats the pants off of wireless. They're dirt cheap on eBay too - equivalent MoCA stuff is pricey.


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## HoTat2 (Nov 16, 2005)

djrobx said:


> I've found that DECAs perform very well with PCs. I can transfer files and get 90% utilization out of the 100mbps ethernet link, about the same as I get from a plain 100mbps switch. There's a little bit of additional latency (~4ms), but the performance beats the pants off of wireless. They're dirt cheap on eBay too - equivalent MoCA stuff is pricey.


+1 here as well;

Just hooked a PC up to my DECA cloud through a dongle, and its working just fine and does indeed beat the hell out of the former WiFi-N adapter I had on it for years.

And Yes I know its against DirecTV's policy and recommendations to do this.

So no one flame me please for heresy against MRV orthodoxy. 

But anyhow, more importantly there are no apparent conflicts when others here are streaming shows via MRV. Whether they be HD MPEG-4 or the even more bandwidth hogging MPEG-2 OTA recordings.

Hey, DirecTV's development of the external DECA dongles coupled with independent sellers on SolidSignal, ebay, and elsewhere for cheap prices may have just inadvertently spoiled the market for the much more expensive formal MOCA 1.1 adapters.


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