MoCA issues

Discussion in 'TiVo Help Center' started by flipper325, Nov 8, 2019.

  1. Nov 8, 2019 #1 of 13

    flipper325 New Member

    Nov 7, 2019
    I have reviewed multiple posts on this forum on how to properly set up the MoCA network, which I found very helpful. Unfortunately I was unable to get mine to work, and am hoping you good folks here can help.

    Background: When we had the house remodeled, I had additional coax and Ethernet pulled into multiple locations, but couldn't get Ethernet into several of the rooms. We have a Roamio Plus and 3 Minis. Roamio and two of the Minis are in rooms that have both coax and Ethernet, and are set up on the Ethernet network. The 3rd Mini however is in a bedroom with no Ethernet, hence the problem.

    I initially tried a pair of powerline Ethernet adapters, but the network was intermittent -- not sure if it's the quality or the length of the powerline wiring. I then tried setting up the MoCA network, by installing the PoE filter between the signal amp and the splitter, and also replacing the 6-way 1 GHz splitter with a 2 GHz. That, unfortunately, didn't work -- Minis couldn't find the DVR when set up as clients (DVR was set up as a bridge.) As this was the guest bedroom I gave up, but we now have a family member staying there and I'd like to put another Mini/TV in the basement, so I would like to get MoCa functioning, if possible.

    Current setup: Diagram is attached, with Ethernet connections highlighted in yellow. The 6-way splitter was replaced by a 3-way going into a 8-way (we now have 10 coax wired locations). Both are 1 GHz, I know I'll need to replace them with 2 GHz units, and reinstall the PoE filter. So several questions:

    1) Is the preferred location for the PoE filter before the signal amp, or between the signal amp and the 3-way splitter?

    2) Is there a better splitter configuration that 3-way into 8-way, to get 10 coax outputs? If I go with a different config (say 2-way into two 6-ways), should unused splitter outputs be capped with 75 Ohm terminators? What about coax outputs in rooms that are wired but not used?

    3) The signal amp installed by Spectrum is PCT model PCT-MA-B1010-1A (PCT-MA-B1010-1P Amplifier - PCT International, Inc.). It is appropriate for the MoCA network, or does it need to be replaced? If replaced, with what? Something like this? PCT-VC-F19A Amplifier - PCT International, Inc.

    Question 3: Cable modem is in the basement (along with the router and Ethernet switch) while the DVR is on the first floor. Do I need a separate coax-Ethernet bridge/adapter? I assumed I didn't, since I had Ethernet at the DVR. Was I wrong? This GoCoax model supports MoCA 2.5 and is actually cheaper than others which only support slower MoCA speeds, would this be a good choice?

    Am I missing anything?


    Attached Files:

  2. Nov 8, 2019 #2 of 13

    ThAbtO TiVoholic by the bay TCF Club

    Apr 6, 2000
    SF Bay Area
    You need to have ethernet cable AND coax to be in bridge mode. You cannot do this if its just the coax connected. Bridge (or host) means its using the Tivo as its host and network traffic will be bridged through the ethernet.
  3. Nov 8, 2019 #3 of 13

    NeuroDawg New Member

    Nov 6, 2019
    Puget Sound, WA
    1. I would put the POE filter on the line coming in from outside, followed by the amplifier, and then the splitter.

    2/3. My cable company (Xfinity) installed an amplifier/splitter with built-in POE filter when I had cable installed in my new home. I would recommend the same. (Commscope CSMAPDU9VP - ~$35 on Amazon) This looks to be essentially the same as the PCT-VC-F19A amplifier you posted (which also has the POE filter built in). As an aside, my installer didn't know there was a filter built in to the amplifier and put one on the line coming in to my house - completely hosed my internet speeds until I realized the issue and took it off. You could add an additional splitter off this to get to your 10 outlets, if you really need all ten to be active a the same time, but I wouldn't put a MOCA device on the additional splitter.

    4 (your question #3). You should be able to set the Roamio to create the MOCA network with your setup. You have both the coax and network plugged into the Roamio. I wouldn't be surprised if the amplifier or splitters are disrupting the MOCA signals. I would try troubleshooting by removing the amplifier and hooking up the mini to the 3-way amplifier. If that works, then add back in the amplifier. If it doesn't work, you know the amplifier is causing the problem. If it does work, then go back to the 8-way splitter with the mini, and if it doesn't work, then you know the issue is with the splitters.
  4. Nov 8, 2019 #4 of 13

    NeuroDawg New Member

    Nov 6, 2019
    Puget Sound, WA
    He has both ethernet and coax coming into his Roamio. He should be able to use it as host/bridge.
  5. Nov 8, 2019 #5 of 13

    snerd Well-Known Member

    Jun 6, 2008
    Leave the PoE filter on the input of the 3-way splitter. Then it won't matter if the amplifier isn't MoCA compliant, since no MoCA signals will be passing through the amplifier.

    Add 75-ohm terminations on all unused splitter ports and/or unused wall plates.

    If only 3 outputs are actually used for the 8-way splitter, it would be better to replace it with a 3-way splitter. Using fewer splits will increase the chances for MoCA to work properly. Going through a 3-way then an 8-way might make the MoCA signals too weak to work reliably, depending on the length of coax going to the various rooms. Assuming the 3-way splitter and 8-way splitter are in the same room, there are many different configurations that could be used to get the best MoCA signals to the rooms where MoCA is actually needed.

    As a (temporary) first step, you could bypass the 8-way completely and connect the coax from the room of the MoCA-only Mini to the output of the 3-way which normally feeds the 8-way splitter. That should eliminate MoCA signals strength from the equation. After getting everything working, you can try putting the 8-way splitter back and see if the MoCA network still works.

    The Minis that are connected directly to ethernet do not need to be connected to coax, unless you really want to preserve the option to connect them through MoCA.

    Be sure the Roamio is configured as a bridge in the Settings menu. There's no real need to add a separate MoCA adapter.
    fcfc2 likes this.
  6. Nov 8, 2019 #6 of 13

    kpeters59 Well-Known Member

    Jun 19, 2007
    Houston, Texas
    Is the 8-way splitter a Unity Gain amplified splitter? They typically won't pass MoCA through the input port.

    If it's not amplified, it's probably dragging your MoCA signal too low. You should swap it for a 3-way.

    Check and document (and post?) your existing MoCA levels.

    What model is your Router / Modem? Who provided it?

    Mini 1&2 don't need both Coax and Ethernet.

  7. Nov 8, 2019 #7 of 13

    fcfc2 Well-Known Member

    Feb 19, 2015
    Mr. Snerd pretty much nailed it in post #5. I am a fan of the Holland brand MoCA rated splitters and if I were you, I would replace the initial 3 way with one of those and replace that 8 way with one of the Holland versions but only with enough ports to support what you are actually using. And yes, it is a good idea to use 75ohm F-type terminators on any coax port which is not in use. The Holland splitters are available via Amazon and this place, Cable and Satellite Tools - Distributor of Tools for CATV, Satellite, Home Theater, Security, Telecom .
    You should not need to replace the builtin MoCA of your Roamio so unless you want MoCA for other networking needs, you can forget that.
  8. Nov 8, 2019 #8 of 13

    fyodor Active Member

    Sep 19, 2006
    Some diagnostic steps:

    1. Do the Minis get Internet or no network connectivity at all? If the former, it may be something other than MoCA?

    2. The minis with Ethernet do not need coax. I would start off by disconnecting the Coax from those and just connecting them via Ethernet and seeing if they work. This would isolate whether it is in fact a MoCA problem vs. some other kind of networking issue.

    3. My vague recollection is that splitters with very large numbers of ports have detrimental effects on MoCA, basically with some kind of 1/N^2 type of signal reduction, so the 8 port splitter may be causing trouble. Can you disconnect the splitter and just feed the input into the port going to the "Mini 3" room. Does that do anything?

    4. To answer your specific question, I'd probably just use a splitter with as many ports as you are actually using and just have the coax for the additional rooms be disconnected.
  9. Nov 8, 2019 #9 of 13

    flipper325 New Member

    Nov 7, 2019
    Thanks very much to all who responded! The advice seems to be pretty consistent, so this is my plan of action:

    1) Disconnect coax cables from splitter outputs for the two Minis that have both coax and Ethernet. This will reduce the number of coax output requirements by 2.

    Disconnect coax cables from splitter outputs for the rooms that are wired up but where nothing is hooked up at this time --5 more.

    This will leave only 3 required coax outputs -- modem, Roamio DVR, and one Mini.

    2) Replace the 3-way 1 GHz splitter with MoCA-compliant 2 GHz unit, removing the 8-way splitter altogether.

    3) Reinstall the PoE filter, either before the amp, or after the amp before the 3-way splitter (to see if it would make a difference).

    4) Reenable MoCA on the Roamio and check if the no-Ethernet Mini can now see it.

    Long-term, I would still like to have MoCA with more than 3 coax outputs, but I'm clear on always keeping the number of outputs to the min. required. Will deal with adding extra outputs as the need arises, assuming it will work now with 3.

    My modem is provided by Spectrum, it's Hitron E31N2V1 (DOCSIS 3.1 eMTA)
    My router is Netgear RAX80/AX8 (5 Ethernet ports)
  10. snerd

    snerd Well-Known Member

    Jun 6, 2008
    Note that DOCSIS 3.1 can clash with MoCA depending on how Spectrum assigns channels for the modem. You might want to check which frequencies are used by the modem. If there is a clash, there will be additional hoops to jump through to get MoCA working.

    If there is a clash, adding a PoE filter upstream from the modem will probably nuke your external ethernet. That can be resolved by adding a 2-way splitter between the amplifier and the 3-way splitter, and putting the PoE on the input of the 3-way, while connecting the other output from the 2-way splitter to the modem. This also means the 3-way splitter could be exchanged for a 2-way splitter for best signal strengths.
    Last edited: Nov 8, 2019
  11. flipper325

    flipper325 New Member

    Nov 7, 2019
    Thanks, got it. A few follow-up questions:

    1) I know that splitters for MoCA need the bandwidth above 1 GHz, but I've also read that 3 GHz splitters spec'd for satellite systems can also cause issues, and 1.5-2 GHz was optimal. Is that correct?

    2) Is there anything special about the $15 TiVo-'authorized' PoE filter As say compared to this one

    3) Spectrum restricts customer access to modem setup/status settings, but their tech support read off upstream and downstream data channel frequencies for me (not without forceful prodding) -- in MHz below. How can I tell if these would clash with the MoCA in the Roamio?
    a) Where in the Roamio settings would I see the MoCA frequencies?
    b) How close is too close? 0.2 Mhz, 0.5 MHz, etc.?

    Upstream (4)

    Downstream (32)
    507 633 585 537
    675 627 579 531
    669 621 573 525
    663 615 567 519
    657 609 561 513
    651 603 555 501
    645 597 549 495
    639 591 543 0
  12. fcfc2

    fcfc2 Well-Known Member

    Feb 19, 2015
    #1 Close but not exactly, MoCA rated splitters like the Holland brand are "rated" for 5-1675MHz which covers the needed MoCA range. Further, the MoCA range on these MoCA rated splitters are reported to have lower port isolation at the MoCA frequencies to ease the flow of MoCA signals. In practice these MoCA rated splitters have resolved issues other brands have not.
    Many splitter manufacturers have taken to adding terms like "MoCA capable" or "MoCA compatible" in their product descriptions. This is marketing smoke and mirror stuff because all splitters are generally capable of being used with MoCA. There are also older Verizon and Sunburst brands which are MoCA rated and there are some newer products from Extreme Engineering which appear to be actually enhanced to perform better on MoCA systems also.
    #2 Tivo recommends the use of a MoCA filter with 70-80dB of band rejection on their OTA systems where as the less expensive and more common standard MoCA filter/ Whole Home DVR filter have roughly 35-40dB of band rejection.
    Most folks seem to have gotten by with the much less expensive MoCA filters on the more common MoCA applications but I have seen zero complaints from folks using the standard MoCA filters even on OTA applications.
    #3 The issue of some CATV systems using part of the MoCA band to achieve higher broadband speeds is not common and not problematic unless you are using a newer Docsis 3.1 modem and the symptom is that when MoCA is enabled, your internet speed is trashed dramatically. A MoCA filter upstream is problematic and the solution is to provide a direct run from the ISP to the cable modem and this sometimes requires the use of a single 2 way first to provide a "clean" run directly to the cable modem and the MoCA filter to be applied on the other leg of the 2 way when MoCA is being used.
  13. snerd

    snerd Well-Known Member

    Jun 6, 2008
    fcfc2 covered it well. Some additional comments:

    1) My personal opinion is that MoCA rated splitters are a gimmick, not unlike Monster Cables. The decreased port isolation is a doubled-edged sword. It can help in some situations (especially when no PoE filter is used) and it can make things worse in other situations. It is best to use splitters rated for at least 1675MHz (1.675GHz) for compatibility with MoCA 2.0/2.1/2.5. I use ordinary splitters rated for 2.4GHz and have never encountered issues.

    2) There are two features of the PoE filter that are important: A) it acts as a mirror to reflect upstream MoCA signals back down through the coax plant, which dramatically improves signal stength, IMO this is the most important reason for using a PoE filter. B) it provides isolation to prevent your MoCA network from interacting with MoCA devices on a neighbor's network. The higher isolation of the "TiVo approved" PoE filter is better if you're worried about outsiders trying to tap into your MoCA network. I have a brother who doesn't use a MoCA filter but claims his system works fine. I always recommend them, mostly for feature A) above.

    3) The frequencies listed won't clash with MoCA. TiVo uses MoCA band D frequencies that range from about 1125MHz to 1525MHz. Newer MoCA 2.0/2.5 go up to 1675MHz.

    3a) "Settings & Messages" / "Network Settings" / "Network Troubleshooting" / "Network Status" lists info about the MoCA network. Only the channel is given, but this post shows the mapping between channel and frequency. My network is on channel 17 at 1200MHz.

    3b) Based on the frequencies provided by Spectrum, I'm guessing that your modem is using DOCSIS 3.0 protocols. DOCSIS 3.0 bands are the same 6MHz bands used for digital catv. That is why many of the listed frequencies are 6MHz apart. The max frequency used at 675MHz is well below the MoCA band D frequencies, so there should be no issues with your modem. DOCSIS 3.1 uses bands that range from 24MHz to 192MHz at frequencies up to 1218MHz and/or 1794MHz depending on which document is referenced. I don't know the whole story, and it appears that things are still in flux.

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