Comcast Hates my MoCA Setup

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Dodge DeBoulet

Occasional Visitor
tldr; Actiontec ECB6200s make noise on neighborhood cable, POE filter no help. Comcast no like, install other filter make cable modem sad. Want happy cable modem. Want comcast calm down.

I've had some issues with internet connectivity over the last 3 weeks. Mostly it would work fine during the day, but early morning and late afternoon would see some interruptions. I asked Comcast to check things on their end and they did not see any problems in my area. My modem (until this morning a Motorola SB6141) would lose sync and cycle through downlink/uplink/transport (or whatever the "globe" icon means) multiple times and eventually connect. The status page at http://192.168.100.1 showed 8 downstream channels bonded and 1 upstream bonded, with the other 3 timing out.

Repeated calls to Comcast eventually resulted in a theory (by a Comcast rep) that it was either a Comcast external cabling issue or my modem. They agreed to roll a truck which came today. In the meantime, I took the proactive measure of replacing the SB6141 modem with a NetGear CM1000v2. That seemed to improve reliability; 32 channels down bonded, but only 4 out of 8 up. Similar timeouts appeared in the cable modem's log.

When the technician arrived, he started off by saying that my problem was most likely triggered by noise generated by my coax infrastructure; Comcast discovered the noise on the local "leg" a while back and apparently installed a low-pass filter of some sort that stripped out the upper channels that would normally have been available to my modem for uplink bonding. It didn't completely fix the problem for them, but it helped.

He used a signal/spectrum analyzer to look at all of my coax connections, and came to the conclusion that the noise was generated by one or more of my four Actiontec ECB6200 MoCA2 adapters, which provide connectivity to equipment at both ends of my house PLUS a garage/apartment outbuilding that my father-in-law lives in. He saw both bursty electrical noise and AM/FM band interference. This was apparently being soaked up somehow by my coax and pushed to Comcast's neighborhood infrastructure. The technician told me that it was unlikely that I would be able to continue to use the Actiontec solution, which has been rock-solid for the last 3+ years and quite fast enough for my purposes.

A bit of background on the cable topology ... Comcast service enters the basement and is connected to a distribution amp through a POE MoCA filter. Coax is run to most every room in the house (large house, ~ 4000sf on 2 floors) with a 225ft leg underground to my father-in-law's apartment. One leg of the distribution amp runs to the cable modem near to the primary house router, and an ethernet run goes to an ECB6200 near the distribution amp. The ECB6200 is connected via a short length to the distribution amp. There are 3 other ECB6200s; one in the media room at one end of the house, another in the living room at the other end of the house, and the last one in my FiL's apartment. And as I said, It's all been working great for over 3 years.

Now Comcast is saying that I need to stop injecting crap into their network and they're blaming it on the ECB6200s according to the analysis done by the tech. I can't deny that they're the problem; he showed me what was happening. Since we don't use most of the coax for cable TV, I'm considering a topology change that would isolate the MoCA network from Comcast's service connection.

Any other options? Has anyone else experienced this with the Actiontec hardware?
 

degrub

Very Senior Member
What moca POE filter are you using ?
try a Holland branded one and see if that makes a difference.
Otherwise, i would isolate from comcast.
 

SomeWhereOverTheRainBow

Very Senior Member
tldr; Actiontec ECB6200s make noise on neighborhood cable, POE filter no help. Comcast no like, install other filter make cable modem sad. Want happy cable modem. Want comcast calm down.

I've had some issues with internet connectivity over the last 3 weeks. Mostly it would work fine during the day, but early morning and late afternoon would see some interruptions. I asked Comcast to check things on their end and they did not see any problems in my area. My modem (until this morning a Motorola SB6141) would lose sync and cycle through downlink/uplink/transport (or whatever the "globe" icon means) multiple times and eventually connect. The status page at http://192.168.100.1 showed 8 downstream channels bonded and 1 upstream bonded, with the other 3 timing out.

Repeated calls to Comcast eventually resulted in a theory (by a Comcast rep) that it was either a Comcast external cabling issue or my modem. They agreed to roll a truck which came today. In the meantime, I took the proactive measure of replacing the SB6141 modem with a NetGear CM1000v2. That seemed to improve reliability; 32 channels down bonded, but only 4 out of 8 up. Similar timeouts appeared in the cable modem's log.

When the technician arrived, he started off by saying that my problem was most likely triggered by noise generated by my coax infrastructure; Comcast discovered the noise on the local "leg" a while back and apparently installed a low-pass filter of some sort that stripped out the upper channels that would normally have been available to my modem for uplink bonding. It didn't completely fix the problem for them, but it helped.

He used a signal/spectrum analyzer to look at all of my coax connections, and came to the conclusion that the noise was generated by one or more of my four Actiontec ECB6200 MoCA2 adapters, which provide connectivity to equipment at both ends of my house PLUS a garage/apartment outbuilding that my father-in-law lives in. He saw both bursty electrical noise and AM/FM band interference. This was apparently being soaked up somehow by my coax and pushed to Comcast's neighborhood infrastructure. The technician told me that it was unlikely that I would be able to continue to use the Actiontec solution, which has been rock-solid for the last 3+ years and quite fast enough for my purposes.

A bit of background on the cable topology ... Comcast service enters the basement and is connected to a distribution amp through a POE MoCA filter. Coax is run to most every room in the house (large house, ~ 4000sf on 2 floors) with a 225ft leg underground to my father-in-law's apartment. One leg of the distribution amp runs to the cable modem near to the primary house router, and an ethernet run goes to an ECB6200 near the distribution amp. The ECB6200 is connected via a short length to the distribution amp. There are 3 other ECB6200s; one in the media room at one end of the house, another in the living room at the other end of the house, and the last one in my FiL's apartment. And as I said, It's all been working great for over 3 years.

Now Comcast is saying that I need to stop injecting crap into their network and they're blaming it on the ECB6200s according to the analysis done by the tech. I can't deny that they're the problem; he showed me what was happening. Since we don't use most of the coax for cable TV, I'm considering a topology change that would isolate the MoCA network from Comcast's service connection.

Any other options? Has anyone else experienced this with the Actiontec hardware?
I use a mixture setup, 2 Zyxel HLA4205 which is a 6802ECB Board that uses band D extended range, and 2 Actiontec ECB6200. There are ways to adjust the band frequency ranges of these moca 2.0 bonded devices. The Band D extended range operates in 1125-1675MHz of frequency. The biggest problem with these moca devices is to achieve the best performance, they compete with the frequency ranges of most of your big Television providers such as comcast, u-verse, or satellite. Fortunately, my home had seperate wiring for satellite and cable. I do not use satellite so my moca runs using the original satellite coxial network. Comcast installed their own wiring when I originally signed a service agreement. Back to the talk on moca- if you dont mind less performance on these moca adapters, by using the IP address assigned to them by your router, you are able to adjust their frequency ranges.
1603935618918.png

On my network the ip address assigned to my Zyxel moca adapter is 192.168.1.3. Here I am able to adjust the frequency.
1603935687691.png

You would probably have to do this with each moca adapter.
 

SomeWhereOverTheRainBow

Very Senior Member
Another factor when using Moca, when you have splits in your coxial network, you want to make sure all the splitters you use are adequate to support higher band moca ranges. Using inadequate splitters can cause issues with frequencies in moca signals.
 

Dodge DeBoulet

Occasional Visitor
What moca POE filter are you using ?
try a Holland branded one and see if that makes a difference.
Otherwise, i would isolate from comcast.
It's a Holland ... this one. The Comcast tech actually told me I should NOT have installed it; they handle any filtering required. I remember specifically talking to Comcast tech support (I know, I know) about that when I first set it all up and received no objections.
 

degrub

Very Senior Member
i would guess it is not the Actiontecs injecting noise, but a poorly terminated coax connection or a ground loop or a broken shield (so that it is not grounded on one end). Any of these can pick up electrical noise from motors, three phase electrical, small switching power supply issues, or poorly designed consumer stuff that radiates and gets induced on the coax. Your underground run is one possible source if there are stray ground currents. It would take the same type of gear the tech had and a lot of hunting to find the issues.

Did you run the experiment of powering off all of the Actiontecs while the tech was there ?

They will want to blame the customer's gear and installation as a starting point even if the issue is with their cable plant.
 

Dodge DeBoulet

Occasional Visitor
Another factor when using Moca, when you have splits in your coxial network, you want to make sure all the splitters you use are adequate to support higher band moca ranges. Using inadequate splitters can cause issues with frequencies in moca signals.
There's only one splitter. It's the distribution amp, a Commscope CSAPDU9VP ... Forward 54 - 1002 MHz Gain 0dB, Reverse 5 - 42MHz, Gain 0dB. I don't think this would present an issue.
 

SomeWhereOverTheRainBow

Very Senior Member
Normally comcast installs a moca filter at the line coming into the house. In general it is sufficient to do the job. It is mainly used to attenuate the cable frequency for the cable devices in your network, while preventing output noise to the neighborhood cable network.
 

SomeWhereOverTheRainBow

Very Senior Member
There's only one splitter. It's the distribution amp, a Commscope CSAPDU9VP ... Forward 54 - 1002 MHz Gain 0dB, Reverse 5 - 42MHz, Gain 0dB. I don't think this would present an issue.
My self supplied splitter ranges from 5-1675mhz. Your splitter is decent for slightly older moca network, but it is taking that higher Cable frequency and higher moca adapter frenquency and forcing the two to compete. My comcast supplied splitter at my box goes even higher in range.
 

degrub

Very Senior Member
There's only one splitter. It's the distribution amp, a Commscope CSAPDU9VP ... Forward 54 - 1002 MHz Gain 0dB, Reverse 5 - 42MHz, Gain 0dB. I don't think this would present an issue.
That splitter won't be passing any MOCA2 signal anyway in any direction. Your moca2 runs are not passing through that, correct ?

it would help if we had a sketch of your cable layout and the type and location of all the devices on the coax
 

Dodge DeBoulet

Occasional Visitor
i would guess it is not the Actiontecs injecting noise, but a poorly terminated coax connection or a ground loop or a broken shield (so that it is not grounded on one end). Any of these can pick up electrical noise from motors, three phase electrical, small switching power supply issues, or poorly designed consumer stuff that radiates and gets induced on the coax. Your underground run is one possible source if there are stray ground currents. It would take the same type of gear the tech had and a lot of hunting to find the issues.

Did you run the experiment of powering off all of the Actiontecs while the tech was there
Just the one located near the distribution amp. With that shut off, some of the electrical noise went away.

They will want to blame the customer's gear and installation as a starting point even if the issue is with their cable plant.
Comcast be Comcast ... the area manager is coming over tomorrow to take a look at the situation. The tech, who claimed he's been doing this for 15 years, had apparently never seen a MoCA installation configured and used the way I'm using it (which, to me, hardly seems atypical). He actually said that "the normal way you'd do this is to run Ethernet to each location." Uh, duh, it's a 4000sf house with a PRE-EXISTING coax plant. Why the f-bomb would I pull Cat6 when I can drop a hundy or two on some technology that neatly solves the issue?

I think I'm just going to pull the TiVo VOX from the media room and stick it near the cable modem. That and the cable modem will be on a splitter from the service connection, ethernet from the VOX to the main router, and a run from the router to an ECB6200 that feeds the coax network. And if I want to watch recorded stuff in the media room, I'll just install one of the newer Minis that doesn't suck (as bad).
 

krkaufman

Senior Member
I'm considering a topology change that would isolate the MoCA network from Comcast's service connection.
Seems like a good idea, if only to eliminate it as an excuse for Comcast.

Any other options?
TiVo offers a "PoE" MoCA filter w/ supposedly minimum 70 dB loss in the stopband. (link) Though unnecessary if isolating the modem feed from MoCA.

I'm also curious as to what model amplifier you have.
 

Dodge DeBoulet

Occasional Visitor
That splitter won't be passing any MOCA2 signal anyway in any direction. Your moca2 runs are not passing through that, correct ?

it would help if we had a sketch of your cable layout and the type and location of all the devices on the coax
Everything flows through the CSAPDU9VP. It's been working fine for 3 years now. There's a POE filter on the service connection from Comcast.

I'll do up a diagram and post it. Might not be tonight though.
 

SomeWhereOverTheRainBow

Very Senior Member
Everything flows through the CSAPDU9VP. It's been working fine for 3 years now. There's a POE filter on the service connection from Comcast.

I'll do up a diagram and post it. Might not be tonight though.
If you pay for their servicing fee, comcast can drop some new topology for ya no extra cost (for your cable networking). (Atleast they did for me since I am paying for their service protection). That is how i got to use the old coxial for my moca. :D;)
 

Dodge DeBoulet

Occasional Visitor
I'll follow up tomorrow after I've talked to the area manager. I'm not currently paying for any service protection; I don't have any Comcast hardware other than a cable card (and they may own the amp, for all I know ... it was here when we bought the place).
 

krkaufman

Senior Member
Everything flows through the CSAPDU9VP.
If troubleshooting MoCA, one thing missing from the conversation are the current MoCA statistics for your network. Checking/posting the stats would help understand the performance of the MoCA network at a more detailed level than just a LAN or Internet speed test, which can gloss over borderline performance situations. Critical info are PHY rates and power levels.
 

Dodge DeBoulet

Occasional Visitor
If troubleshooting MoCA, one thing missing from the conversation are the current MoCA statistics for your network. Checking/posting the stats would help understand the performance of the MoCA network at a more detailed level than just a LAN or Internet speed test, which can gloss over borderline performance situations. Critical info are PHY rates and power levels.
Well, I'm not really troubleshooting MoCA performance ... speeds are fine. I just need to keep the noise it's generating off of Comcast's local infrastructure. The POE filter is doing it's part for the MoCA frequencies, but not for the other noise that is somehow being generated by these ECB6200s.
 

degrub

Very Senior Member
I wonder if the distribution amp’s band pass filter is interacting withe the higher frequency moca 2 modems that are likely having to run on moca 1 or 1.1 bands.
 

krkaufman

Senior Member
Well, I'm not really troubleshooting MoCA performance ... speeds are fine. I just need to keep the noise it's generating off of Comcast's local infrastructure. The POE filter is doing it's part for the MoCA frequencies, but not for the other noise that is somehow being generated by these ECB6200s.
MoCA performance, as I mentioned, goes beyond the speeds that you're experiencing. However unlikely, the amount of power required to establish and maintain the MoCA connections may be a factor.

Re: the ECB6200's ... have you capped all unused "TV/STB Out" pass-through ports w/ 75-ohm terminators? And the same for any unused ports on the amplifier?

I wonder if the distribution amp’s band pass filter is interacting withe the higher frequency moca 2 modems that are likely having to run on moca 1 or 1.1 bands.
It would be interesting to know.
 

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