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.

[dexman]

I just had another thought. All twelve of the taps have cables connected to them. Are all of the taps actively being used? 🤔

If not, would it be possible to determine the active ones, install smaller splitters, label the cables and move them to the smaller splitter. 

Smaller splitter = less attenuation  = stronger signal. 🙂

[Edg1]

I'd definitely give rid of the amp and go ONT to two port. Then one side of the two port to the router and the other side feed the 6 port with all the stbs and extenders. Also if any of the extenders are next to a IP client  then get rid of the two port and connect them with ethernet instead. 

Maybe OP can use a friend or family me to isolate all the coax. 

[jdramm]

Hi all,

Thanks for the help. I’m suspecting attenuation as well. I also found the MoCA alliance ‘best practices’ that discusses the port-port impedance / attenuation of splitters. Here’s the link to that: MoCA alliance best practices 

Here’s how I now understand my situation, and what I’m going to do. I’m trying to write this in a way that is helpful to others, just as I appreciate the posters helping me!

The six-way splitters are 11.5dB from in to any of the splits. They do NOT mention MoCA, but they do say 5-1000MHz. (PDI-6WMVS-5, which Google only gives me eBay and some old VZ posts.)

The set-top boxes get their signal from the coax leaving the ONT shown in the picture. That, at least, goes through the MoCA bypass amplifier, then the splitters (11.5 + 3.5, total 15dB), so between the ONT and the STBs, all is good.

The network is NOT taking the same path. It goes from the ethernet RJ45 port on the ONT to the router WAN port. The router is then going out over coax to one of the six-way splitters. That’s probably giving me a marginal signal level (not a MoCA splitter, and not ‘driving’ from the front the way the ONT does).

So, I’m going to replace the six-way splitters with eight-way 5-1675MHz MoCA splitters (arriving Friday) and look to consolidate the extenders and the router on to one of the splitters. (It’s about time I labeled the cables, anyway.) I’m undecided whether to consolidate the STBs on to the same splitter. On the one hand, they shouldn’t care. On the other hand, who knows what they’re doing?

BTW, I have looked in the logs and statistics a few times, and not seen anything. The ‘LAN coax statistics’ (“Only advanced technical users should use this feature” according to my router) report low 600s for the STBs and around 3000 for all three extenders), which seems high enough. Couldn’t see anything relevant in the ‘back haul’ (BHM) logs on the extenders — unless the lines posted after my signature mean anything to someone? 

I’ll post an update over the weekend once I’ve tried this out.

Thanks all,

John.

Typical extract from BHM log on an extender (it does occur every 10s, which kind of ties into the every 10 minutes I have a network outage):

2022 Mar 23 18:50:17 BHM notice [BHM.5] [BHM] set_led_status_for_bh(1077) > BHM_LED_ESTABLISH_WIRE_BACKHAUL

2022 Mar 23 18:50:17 BHM notice [BHM.5] [BHM] set_led_status_for_bh(1038) > new_status=4 curr_status=4

2022 Mar 23 18:50:17 BHM warning [BHM.4] [BHM] main(543) > owl_sys.bhm.ARC_EX_BH_IND: eth2, ip: 192.168.1.105

2022 Mar 23 18:50:06 BHM warning [BHM.4] [BHM] main(543) > owl_sys.bhm.ARC_EX_BH_IND: eth2, ip: 192.168.1.105

2022 Mar 23 18:49:56 BHM warning [BHM.4] [BHM] main(543) > owl_sys.bhm.ARC_EX_BH_IND: eth2, ip: 192.168.1.105

2022 Mar 23 18:49:46 BHM notice [BHM.5] [BHM] set_led_status_for_bh(1077) > BHM_LED_ESTABLISH_WIRE_BACKHAUL

2022 Mar 23 18:49:46 BHM notice [BHM.5] [BHM] set_led_status_for_bh(1038) > new_status=4 curr_status=4

2022 Mar 23 18:49:46 BHM warning [BHM.4] [BHM] main(543) > owl_sys.bhm.ARC_EX_BH_IND: eth2, ip: 192.168.1.105

[dexman]

When calculating loss/attenuation, the coaxial cable needs to be taken into account. Manufacturers publish the data for their products for reference.

A while back I posted the steps for calculating loss. The information was provided to me by the highly respected owner of an Interconnect in New York City.

[jdramm]

Agree, cable losses can add up. The MoCA guide I linked to covers those in table 9. I’ve probably got 200 to 250’ ft of end-to-end cable, RG6, adding another 15 to 22dB of attenuation.

[Cang_Household]

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@John70 wrote:

The six-way splitters are 11.5dB from in to any of the splits. They do NOT mention MoCA, but they do say 5-1000MHz. (PDI-6WMVS-5, which Google only gives me eBay and some old VZ posts.)

---

5-1000MHz excludes MoCA frequencies. I am fairly confident that using these non-MoCA-compatible splitters is sufficient to cause your issue. When a field technician did your installation, did he/she check whether your splitters are MoCA compatible? Field technicians can give you free splitters up to 8-ways.

[jdramm]

Yes, I think a more appropriate splitter will hopefully resolve it. Not calling out a VZ tech for that, though. I’d rather do it when convenient for me. Appreciate the info.

We haven’t had the house from new. I don’t think the most recent installer checked. It’s been like this for a while — just ‘not quite right’ but it’s taken a long time to track down what is ‘not quite right’!

[dexman]

I thought I might share my coaxial situation here at the house.

Our house's coaxial cabling was a bit of a hodgepodge. Last year I cleaned it all up. For splitters, I needed only two....a three-way and a two-way.

I went with Belden 1189A & 1613R RG6 coax, a Philmore CS203EN and a CS202EN splitters (an electronics retail store in our area sells Philmore products).

The splitters are power pass so they can be used with satellite service as well as CATV and OTA applications with a range of 5 to 3000MHz.

Cables were terminated with Arris Digicon DS6Q compression connectors. I ordered that brand because Verizon was using Digicon connectors back in 2008 when I had FiOS installed. Today Verizon uses Belden/PPC cable and connectors like Comcast and other companies do.

FiOS television has been rock solid. When I had my three 3200 extenders connected via coaxial cable, they too had no problems. 🙂

[jdramm]

OK, so I installed my new MoCA-rated 8-way splitter, labeled and verified all of the cables (simple cable tester), and set it all back up.

No diffference.

Speeds are great most of the time, but every ten minutes receive disappears entirely. Again, doesn’t happen at the main router, just the satellites. Wired or Wi-Fi.

Any fresh ideas?

Thanks,

John.

[dexman]

Has the amplifier been removed from the system, or is it still connected? 🤔 

[jdramm]

Hi dexman,

I had the amplifier in, but I've also now tried it without the amplifier -- same problem.

(I also confirmed that the ONT coax is only delivering TV to the STBs -- without the ONT coax connected, my internet access still works, as it's coming from the router's coax.)

So, I'm now on a new MoCA 8-way splitter, ONT direct to splitter 'input', and still get no incoming packets for a second or so, once every ten minutes.

Decided to also try ONT and router each going into a 2:1 splitter, and using the output of the splitter to feed into the 8:1 splitter. Again, everything works apart from losing incoming packets every ten minutes.

I ran two PCs using wifi to the same extender, and confirmed they both lose incoming packets at the same time. Have done similar tests with the extender ethernet ports -- it's not a wifi issue.

Running out of ideas. All signal levels look great in the diagnostics on the router and extenders.

Thanks,

John.