MoCA drops receive only every ten minutes

[jdramm]

Hi,

I have a G3100 router, and 3 E3200 extenders.

All three extenders are connected by MoCA (coax), as are our several set-top boxes.

All works fine, except that every ten minutes the extenders stop receiving packets for a few seconds. Transmit is unaffected. This interrupts things like streaming, VoIP phones, conference calls, etc.

Connecting directly to the G3100 does not show this issue.

I’ve been using the StarTrinity continuous IP speed test tool to test this, with a really low (250kbit/s) test. It clearly shows loss of incoming packets for a few seconds, every ten minutes.

I can’t see anything relevant in either the router or the extender logs.

Everything has been restarted multiple times.

Can’t find any loose connections on the coax lines.

Any ideas on how to better isolate and resolve this?

Thanks,

John.

[Cang_Household]

Do you have any interfering MoCA/Coax devices in the coaxial wiring?

For example, MoCA 1.1 used in older Fios STBs. Previous/current cable connection coming from the streets. Incompatible coaxial splitters/amplifiers. Point-of-Entry filters.

[dexman]

The trouble description doesn't note which model STBs are present. Verizon currently deploys Arris 4100 series units, but it is still possible that old Motorola STBs are still out there. STB's do provide error counters that can point to cabling problems.

For coaxial cable connections, poorly applied connectors can cause issues. Other sources of trouble include connecting large port-count splitters in series and having open taps on splitters.

Could a few pictures of some of the coaxial cable hardware along with an STB and the ONT be posted for us? Note that submitted pictures are queued for Moderator review before they appear.

[jdramm]

Hi,

Thanks for the pointers.

I have a VMS4100, a VMS4100P2, two IPC4100s connected by MoCA, and one IPC4100 connected by Wi-Fi.

Short-term error count is zero on all of the STBs connected by MoCA. (I haven’t looked at the Wi-Fi one — should not be relevant.)

I’ll upload some photos later.

Thanks,

John.

[dexman]

I'm not familiar with the P2 STB. The other devices are currently supplied by Verizon. I'll defer to a CL on that unit. 🙂

[jdramm]

P2 STB came from Verizon as well. We hit a limit on boxes or something and ended up with the (very user-unfriendly) two-DVR solution.

Coax in electrical room comes from Verizon ONT box to PDI MoCA bypass amplifier PDI-MBA-101-A. Power light is on for that.

Output then goes to a 1:2 splitter (passive) and each of those two outputs go to 1:6 passive splitters. The G3100 coax is connected to one of the ports in the 1:6 splitters. I don’t know which ports (I.e., on the same 1:6 splitter or not) go off to the extenders.

The G3100 Ethernet WAN port is connected to the ONT. As I’ve said, when I go directly to the G3100, all works great.

Photos below. And before anyone asks, no the Ethernet cabling on the left doesn’t go to useful places… I wish!

[dexman]

I'll always defer to the CLs, but these are my thoughts.

I'm wondering if the amplifier is boosting the signal from the ONT enough to overcome attenuation introduced by the six-way splitters, cable runs and any splitters downstream.

Two-way splitters attenuate the incoming signal a maximum of 3.5db. Per the Allen-Tel online catalog, 6-way splitters attenuate by a maximum of 15db. 

https://www.allentel.com/product/6-way-coax-splitter-2-4-ghz/

So, adding 15+3.5 yields a maximum attenuation of 18.5db. Then adding in attenuation introduced by the coaxial cable itself and any additional splitters downstream, attenuation could be a factor if the amplifier isn't working properly.

[Cang_Household]

Dexman, you might want to summon Clem53 and Edg1 here.

To the OP, any reason to use the signal amplifier in the first place? RF video from the ONT should be strong enough to deliver to STBs around the house. Given the image does not detail the labels on the 6-way splitter, is the splitter MoCA compatible, i.e. have a passthrough range exceeding 1000MHz and to at least 1675MHz? Could you also double check whether there's cable coming from the streets?

Also, if the OP wants to dig into router's log, you can look for MoCA interface error.

[dexman]

I'll send PMs to both shortly. Googling the amplifier's model number yielded a match that indicated that it is a unit that Verizon supplies.

The label on the amp matches the label on the MoCA splitters that Verizon provided a while back. The label on non-MoCA splitters have a different look.

[clem21]

I'd start by removing the first splitter and Amp from the system, running only one of the large splitters direct to the ONT to see if the problem still occurs. If that works OK, switch large splitters and see if that group works OK. If both do, the 2 way splitter or the amplifier are the problem and would need to be replaced or the signal is just too weak to operate the system. Also where does the G3100 get its signal, and which port? You want to make sure it receives the strongest signal possible,  so check the attenuation labels on the splitters and use the lowest one. The Amp could also be over driving the first splitter, try eliminating that from the system.