Spectrum Gig MOCA issue

[krkaufman]

Spectrum sent me another modem. But that didn't fix the issue.

Just so we’re on the same page, what was the issue needing correction (addressed by a modem change)?

 

[krkaufman]

So I just ordered 3 GoCOAX 2.5 MOCA adapters and an Antronix 5-1675 3- way(attic) and 2-way(living room) splitters. I will have to run them on Band -D High. Any idea of what bandwidth I might see out of this setup?

Operating the MoCA 2.5 adapters at D-High (1350-1675 MHz) would possibly give you 3 bonded channels, so 1200 Mbps shared max. (So at least moving beyond the 800 Mbps bottleneck discussed in the OP.)

As stated previously, if your provider is really beginning to use expanded DOCSIS 3.1 frequencies above 1002 MHz, the best plan, if at all possible, is getting the DOCSIS feed isolated from the MoCA coax. And if they’re not and the D3.1 modem is just getting flaky with MoCA signals hitting its circuitry, a MoCA filter installed directly on the modem’s coax port is a good workaround until you can get the modem feed isolated (and ready for DOCSIS 3.1+), allowing you to operate the MoCA adapters at full capacity.

 

[Unibrowser]

Operating the MoCA 2.5 adapters at D-High (1350-1675 MHz) would possibly give you 3 bonded channels, so 1200 Mbps shared max. (So at least moving beyond the 800 Mbps bottleneck discussed in the OP.)

As stated previously, if your provider is really beginning to use expanded DOCSIS 3.1 frequencies above 1002 MHz, the best plan, if at all possible, is getting the DOCSIS feed isolated from the MoCA coax. And if they’re not and the D3.1 modem is just getting flaky with MoCA signals hitting its circuitry, a MoCA filter installed directly on the modem’s coax port is a good workaround until you can get the modem feed isolated (and ready for DOCSIS 3.1+), allowing you to operate the MoCA adapters at full capacity.

So I looked up the modem specs (Hitron EN2251). It shows it has a build in MOCA shield actually. It's running at 5-1218mhz. So I have the Gocoax adapters on the way as well as some new moca cert splitters. Once I put the new MOCA adapters in Band-D High all should be good

 

[krkaufman]

I turned off all MOCA adapters and wouldn't you know, internet is alive again

When you swapped modem’s, did you retain the MoCA filter on the D3.1 modem’s coax port? If not, get it back in place per your diagram.

‘gist: If simply shutting off your MoCA adapters allowed your modem to stabilize, then:
1) The new modem does appear to be sensitive to MoCA signals;
2) If you hadn’t removed the “PoE” MoCA filter, then it’s still unknown whether your download service either requires or is using frequencies above 1002 MHz, since those would be blocked by the “PoE” MoCA filter.

 

[krkaufman]

So I looked up the modem specs (Hitron EN2251).

Got a link for that?

——

DOCSIS 3.1 Cable Modem | EN2251 | Hitron Americas

A powerful DOCSIS 3.1 cable modem, providing speeds up to 10 Gbps with two voice ports and two Gigabit Ethernet ports. Click for more info.

us.hitrontech.com

​

2.5 Gigabit Port​

Equipped with a 2.5 Gbps Ethernet port, the powerful EN2251-RES can support service plans over 1 Gbps.​

Nice.

* Built-in MoCA immunity filter​

I’d be surprised if this is the case, at least for the MoCA signals that fall within the modem’s operating range, so 1125-1218MHz.

 

[Unibrowser]

When you swapped modem’s, did you retain the MoCA filter on the D3.1 modem’s coax port? If not, get it back in place per your diagram.

‘gist: If simply shutting off your MoCA adapters allowed your modem to stabilize, then:
1) The new modem does appear to be sensitive to MoCA signals;
2) If you hadn’t removed the “PoE” MoCA filter, then it’s still unknown whether your download service either requires or is using frequencies above 1002 MHz, since those would be blocked by the “PoE” MoCA filter.

Sorry I forgot to mention I removed all POE moca filters. It caused error lights on the modem when I had it attached

 

[krkaufman]

Once I put the new MOCA adapters in Band-D High all should be good

You should be able to do this with your current bonded MoCA 2.0 adapters, as well.

But whether you do so with the current or goCoax adapters, you’ll then face the issue of your MoCA signals escaping from your home in the absence of a “PoE” MoCA filter.

 

[krkaufman]

Sorry I forgot to mention I removed all POE moca filters. It caused error lights on the modem when I had it attached

With the MoCA filters all removed (and MoCA adapters presumably powered-off), can you access the modem’s UI to check the frequencies in-use for the upstream and downstream channels?

edit: And do you have any means of testing your download max speed (wired to the modem)?

 

[Unibrowser]

With the MoCA filters all removed (and MoCA adapters presumably powered-off), can you access the modem’s UI to check the frequencies in-use for the upstream and downstream

Just so we’re on the same page, what was the issue needing correction (addressed by a modem change)?

The tech was monitoring it and saw error codes. So they sent me a new one thinking that was the issue.

 

[Unibrowser]

With the MoCA filters all removed (and MoCA adapters presumably powered-off), can you access the modem’s UI to check the frequencies in-use for the upstream and downstream channels?

edit: And do you have any means of testing your download max speed (wired to the modem)?

I did this actually with current adapters but they seemed to be limited to 100mbps in that mode

 

[Unibrowser]

With the MoCA filters all removed (and MoCA adapters presumably powered-off), can you access the modem’s UI to check the frequencies in-use for the upstream and downstream channels?

edit: And do you have any means of testing your download max speed (wired to the modem)?

Yes I'll test here soon. Got hit with covid so it put me behind

 

[krkaufman]

I did this actually with current adapters but they seemed to be limited to 100mbps in that mode

I’d take it up with the vendor if their product can’t meet the basic spec. (Somewhat moot with the goCoax adapters enroute, of course.)

The more critical bit from that post was the latter part:

But whether you do so with the current or goCoax adapters, you’ll then face the issue of your MoCA signals escaping from your home in the absence of a “PoE” MoCA filter.

 

[Unibrowser]

I’d take it up with the vendor if their product can’t meet the basic spec. (Somewhat moot with the goCoax adapters enroute, of course.)

The more critical bit from that post was the latter part:

​

That's not a concern with the MPS right?

 

[krkaufman]

That's not a concern with the MPS right?

You’d have to check with your Internet provider. MoCA privacy may alleviate some security concerns, but the Internet provider may not be thrilled with customer MoCA signals coming onto their lines. And, aside from the loss of the performance benefit of the “PoE” MoCA filter, MoCA signals from neighboring networks may begin to affect performance.

What your ISP should have also provided was a customized MoCA filter, with pass- and stop-bands adjusted for DOCSIS 3.1 “initial rollout.”

 

[Unibrowser]

You’d have to check with your Internet provider. MoCA privacy may alleviate some security concerns, but the Internet provider may not be thrilled with customer MoCA signals coming onto their lines. And, aside from the loss of the performance benefit of the “PoE” MoCA filter, MoCA signals from neighboring networks may begin to affect performance.

What your ISP should have also provided was a customized MoCA filter, with pass- and stop-bands adjusted for DOCSIS 3.1 “initial rollout.”

Got an update for you. I replaced all 3 adapters with the latest Gocoax 2.5 ones. Set them all in Band-D High only. LOF to 1400(this is what the translite documentation recommends). Same issue. Once I introduce the 3rd adapter, the speed gets capped at 95mbps. So after looking at the MOCA chart(attatched) I can see why they recommended 1400. But, I decided to try 1300 for the extra channel bandwidth and still roughly 82mhz away from DOCSIS 3.1(1218mhz). All of a sudden with the 3 adapters connected I now have my gigabit LAN back over MOCA. Seems to be working OK along side the modem. Maybe I'll try 1350 instead, idk. But this worked for me. Internet speed tests are back at 700-800 mbps. That's the most I seem to get from Spectrum's (up to a gig) speed lol.

 

[krkaufman]

But this worked for me. Internet speed tests are back at 700-800 mbps.

Are these speed tests still only being conducted on the gaming PC linked to the router via MoCA? Do you have any ability to test the speeds via a PC/laptop hard-wired via Ethernet to your main router or modem?

Have you been able to get into the configuration UI of one of the goCoax adapters to check its MoCA diagnostics, to see at what PHY rates they're operating?

(edit: p.s. I appreciate the update.)

 

[degrub]

To test your local bandwidth, use IPERF . You will need two, one at each end of the path you are testing. One is server and one is client. Run the foward and backward tests as the results depend on the machines used for testing. You will also want to use parallel streams so you can saturate the moca connections. Don’t use internet tests for local lan testing.

 

[Datalink]

Are you still using the 5 to 1002 Mhz MoCA Point of Entry filter. If so, and Spectrum is actually running QAM or OFDM channels up to and including 1218 Mhz, then you're cutting off the upper channels, above 1002 Mhz, by using that particular MoCA POE filter.

So, in that case, it won't matter what you set for the Lowest Usable Frequency, or LOF, unless of course you set too high and end up disabling one or more of the MoCA channels. That appears to be what you did by setting the LOF to 1400 Mhz initially. That would be my guess.

Fwiw, here's a MoCA 1200 Ghz POE filter that you can use:

https://lindsaybb.com/wp-content/uploads/2021/06/LBB0129_LowPass_filter_LPF700AS_dsheet.pdf

That comes from the following Lindsay Broadband 1.2 Ghz Broadband filter page:

1.2 GHz High- & Low-Pass Filters (HPF / LPF) - Lindsay Broadband

A variety of filters are available to suit your needs in bandwidths up to 1.2 GHz. Their compact size delivers large performance with minimal insertion loss, maximum return loss, and […]

lindsaybb.com

If you skip down to the Low Bandpass filters, you can see the filter indicated above. That filter would allow you to run DOCSIS frequencies, up to 1218 Mhz, if in fact Spectrum is actually using frequencies above 1002 Mhz. You should be able to determine that by either:

1. Logging into the modem to check the Downstream Frequency and perhaps the Upstream Frequency lists. I don't know if Spectrum is still using the lower 5 to 42 Mhz range for the upstream frequencies:

2. Calling tech support and simply asking what is the highest frequency range in use for your particular neighbourhood node. Its possible that the Level 1 tech support might not be able to tell you if they don't have the ability to dive into the frequency ranges. OFDM frequency data isn't necessarily broken out for the Level 1 techs, so, you might have to chat with the Level II techs just to ask a relatively simple question.

I have no idea as to where one might obtain one of those filters. I suspect that you would have to call the company to see if you can obtain one. If you look at the spec sheet, you can see that the filter has an ingress loss of 3 dB. That's pretty high. I think the normal ingress loss is around 1 dB:

Insertion Loss:
5-700 MHz 3.5 dB Max
770-1218 MHz 46 dB Min

I'm assuming that the 46 dB Min figure is at 1218 Mhz and that there's a significant roll-off as you approach 1218 Mhz.

So, keeping in mind your original circuit diagram, that 3.5 dB loss might be a problem, depending on where your current modem signal levels happen to be. If you're able to log into the modem to check the signal levels, you would be able to determine if an additional 2 to 2.5 dB loss if going to cause problems. At the end of the day, that additional loss might be no problem, or it could cause significant issues. It just depends on the current signal levels and the channel types in use, as in QAM and/or OFDM.


Personal opinion, it would still be worth running the following test configuration, just to see what the results are:

1. Cable ingress point -> Modem -> ethernet -> Router ->ethernet -> Pc

2. Cable ingress point -> 5 to 1002 Mhz MoCA POE filter -> Modem -> ethernet -> Router ->ethernet -> Pc

Even if you had to buy a 50 or possibly 75 foot ethernet cable to run reach the pc, it would, or should really show you the highest possible data rate if you had a very short run from the cable ingress point to the modem. Installing the 5 to 1002 Mhz MoCA POE filter would show you if Spectrum is actually using frequencies above 1002 Mhz. If you didn't see any difference between the the two configurations, that would translate to "don't bother chasing down a 1.2 Ghz MoCA POE filter". Just continue using the existing MoCA filter, keeping in mind that Spectrum might end up changing their channel configurations for the QAM and OFDM channels. If and when that happens, having a 1.2 Ghz MoCA POE filter might be advantageous.

Fwiw, the potential overlap between the DOCSIS frequencies and MoCA frequencies is definitely recognized. As DOCSIS frequencies move upwards beyond 1.2 Ghz, that will eventually result in MoCA frequencies shifting upwards as well. Its just a question of when, not if, but it might take a very long time before that ever sees practical use out in the field. Personal opinion, for MoCA users today, it might be much cheaper to consider running an additional RG-6 cable run between the Demarc and the modem location. Even if one had to call in an electrician to snake an RG-6 and possibly ethernet cable from point to point, I suspect that it would be cheaper, compared to buying yet another round of MoCA adapters. If you can do that yourself, so much the better. With a second cable run from the demarc to the modem, that allows the end user to isolate the external ISP connection from the internal Intranet which runs over MoCA adapters. You wouldn't have to use a MoCA filter as there wouldn't be any possibility of data exchange via RG-6 cabling. The only inter change point would be thru the router.

 

[krkaufman]

Insertion Loss:
5-700 MHz 3.5 dB Max
770-1218 MHz 46 dB Min

That’s definitely not a filter to use with DOCSIS 3.1 “initial rollout.” Those specs do explain the model number including “700”; filter cuts off signals above 700 MHz.

edit: to clarify, the filter spec only ensures passing frequencies 5-700 MHz at the max loss value (3.5 dB) or below; from 770-1218 MHz, the filter lays a 46 dB hit on the signal. (Between 700-770, the loss will be somewhere in-between.)

 

[Datalink]

It all depends on the roll-off. If it starts at 700 Mhz and rolls off significantly from there, then yup, its no good. But, if the end figure is the roll-off at or around 1218 Mhz, then it should be usable. It all depends on that loss figure above 700 Mhz and what that is intended to indicate. One would really need to see an ingress loss plot to determine whether or not its suitable. The company claims that its suitable for MoCA ops, so the implication is that the roll-off doesn't occur until much higher in the frequency range. If someone had one of these on hand and the ability to check the signal levels on their modem, it would be easy enough to determine, is the filter performance acceptable or not? Its unfortunate that the spec sheet doesn't present better guidance as to where that upper roll-off begins, and at the present time, I'm not assuming that it starts right at 700 Mhz.