DOCSIS 3.0/3.1 Cable Modems and MOCA

[Mark070]

Hey there,

Recently I helped a family member with his new Google Nest Wifi (yes, he wanted easy and never touch). During this time we were talking about him having Coax already ran to the various rooms and possibly use MOCA for that.

Awhile ago, Best Buy sold him a Arris SB8200 Cable Modem. That modem is a DOCSIS 3.1 Cable Modem. I know the frequencies of those cable modems could collide with MOCA, but ... based on today (using Comcast as provider) would they really? Also, is it possible to tell the SB8200 which frequencies to use?

Side Question .. I have a Netgear CM600 Cable Modem. That is a DOCSIS 3.0 cable modem, and it works great with my MOCA network. The advertising for that Modem says 960 MB (just under GB speeds). The specs say for a 400 Mb/s data plan. Real work testing puts it at 275 Mb/s (roughly). Why are these numbers so wildly off?

Also, if my plan goes above 275 Mb/s, I would look to get the CM1000 Cable Modem (DOCSIS3.1), same question as the start .. colliding with MOCA.

Thanks!
Mark

 

[Booboo22]

DOCSIS 3.1 *could* interfere, depends on the implementation:

"The DOCSIS 3.1 specification requires cable modems to cover the frequency range of 258 MHz to 1218 MHz for the downstream as well as to receive two 192 MHz channels in parallel. Support to 1794 MHz is optional."

https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_application/application_notes/7mh89/7MH89_0E.pdf

 

[jrmtz85]

I moved about 1.5 months ago. I had 1gbit with my old ISP via a DOCSIS 3.1 modem (I wanna say it was the Arris). Never tested MOCA on it, but the admin page noted the highest frequency used at around ~950. At new place I have Spectrum gigabit on the Ubee E31U2V1 DOCSIS 3.1. Have note been able to sign into that admin page, but I have 2 Translite MOCA 2.5's in use (with 2 more on the way) and have had no issues. The adapters show PHY rates of ~3500, so all seems good to me.

 

[njhorn]

I moved about 1.5 months ago. I had 1gbit with my old ISP via a DOCSIS 3.1 modem (I wanna say it was the Arris). Never tested MOCA on it, but the admin page noted the highest frequency used at around ~950. At new place I have Spectrum gigabit on the Ubee E31U2V1 DOCSIS 3.1. Have note been able to sign into that admin page, but I have 2 Translite MOCA 2.5's in use (with 2 more on the way) and have had no issues. The adapters show PHY rates of ~3500, so all seems good to me.

any chance you figured out what bands spectrum is using? I have spectrum gig being installed tomorrow and have moca 2.5 adapters. Thanks!

 

[jrmtz85]

any chance you figured out what bands spectrum is using? I have spectrum gig being installed tomorrow and have moca 2.5 adapters. Thanks!

No, never did manage to sign into the spectrum modem page to view this info. However, I have 3 of the Translite 2.5s, and they're all with 3500 phy rates on my spectrum gigabit with no issues. What's your phy rate on the ones you have setup now, prior to the gigabit install?

 

[njhorn]

No, never did manage to sign into the spectrum modem page to view this info. However, I have 3 of the Translite 2.5s, and they're all with 3500 phy rates on my spectrum gigabit with no issues. What's your phy rate on the ones you have setup now, prior to the gigabit install?

Thanks for the reply. What modem do you have? I think they are giving me the TC4400, but if I'm locked out of the admin page and won't get to enable the second WAN link for link aggregation I'll buy my own Netgear CM1100...

I get 3500 now with my 2 @gocoax adapters... Just as an experiment I just changed LOF to 1400 and uncheck D-Ext and D-Low, and sure enough drops to about 2000 and 3 channels instead of 5. But as I only have the two adapters, and can't see needing more in this house, and my appletv speediest on the other end of the moca is still getting 450/22 (on 400/20 plan), if I need to stay in D-High only I think I'm just fine... Really its only gaming and streaming Netflix and plex (from my nas on the router end of the MoCA run), and gaming on an xbox... It would be nice to be able to use the full range though... Hoping to bend the tech's ear tomorrow to find out more...

On a related note, interested/nervous to hear what he will say about my moca setup... So prior to today I just ran my docsis 3.0 modem off the tv out passthrough on the gocoax... Very clean downstream signal all -4 to -7 dB power and 39ish SNR, only a handful of correctable errors a day... Upstream 4 locked channels at 49 to 50 db... I installed a 5-2300 splitter though today and put the 3.0 modem on one out and the gocoax on the other to prepare for tomorrow (since can run docsis 3.1 modem off the adapter tv out), and while downstream looks about the same (maybe 2-3 db less on downstream which is expected loss but SNR essentially the same), upstream only locks 2 channels... I'm still testing at 22Mbit upstream though on speed tests, so not sure the extra two channels are adding anything...

Not sure what any of that means of course, but interested to see if having a splitter there (tried 2 from different brands both moca compatible up to 2300)

 

[njhorn]

Also, found it interesting that I only had to change the settings on one of my moca adapters, and the other one seemed to change the settings also... weird but cool, and definitely working

 

[jrmtz85]

Thanks for the reply. What modem do you have? I think they are giving me the TC4400, but if I'm locked out of the admin page and won't get to enable the second WAN link for link aggregation I'll buy my own Netgear CM1100...

I get 3500 now with my 2 @gocoax adapters... Just as an experiment I just changed LOF to 1400 and uncheck D-Ext and D-Low, and sure enough drops to about 2000 and 3 channels instead of 5. But as I only have the two adapters, and can't see needing more in this house, and my appletv speediest on the other end of the moca is still getting 450/22 (on 400/20 plan), if I need to stay in D-High only I think I'm just fine... Really its only gaming and streaming Netflix and plex (from my nas on the router end of the MoCA run), and gaming on an xbox... It would be nice to be able to use the full range though... Hoping to bend the tech's ear tomorrow to find out more...

On a related note, interested/nervous to hear what he will say about my moca setup... So prior to today I just ran my docsis 3.0 modem off the tv out passthrough on the gocoax... Very clean downstream signal all -4 to -7 dB power and 39ish SNR, only a handful of correctable errors a day... Upstream 4 locked channels at 49 to 50 db... I installed a 5-2300 splitter though today and put the 3.0 modem on one out and the gocoax on the other to prepare for tomorrow (since can run docsis 3.1 modem off the adapter tv out), and while downstream looks about the same (maybe 2-3 db less on downstream which is expected loss but SNR essentially the same), upstream only locks 2 channels... I'm still testing at 22Mbit upstream though on speed tests, so not sure the extra two channels are adding anything...

Not sure what any of that means of course, but interested to see if having a splitter there (tried 2 from different brands both moca compatible up to 2300)

I've never fiddled with the checkmarks on the bands. I think D-Ext is the only one checked on mine. Never had any issues. Speedtests constantly come in at over 900mbps (usually 920-930), and this is with a PC testing through an adapter, so there's definitely no interference happening for me.

 

[njhorn]

I've never fiddled with the checkmarks on the bands. I think D-Ext is the only one checked on mine. Never had any issues. Speedtests constantly come in at over 900mbps (usually 920-930), and this is with a PC testing through an adapter, so there's definitely no interference happening for me.

Ok good to know . Looks like my speed already updated even though I'm still on docsis 3.0 modem... Now getting 700/40, and looks like still using channels in 500-600 range so far, so I doubt I'll have any issues once I get the new modem and the full speed I'm now paying for... Nice seeing my iPhone get that same speed over wifi also with my wifi 6 ax router

 

[njhorn]

I've never fiddled with the checkmarks on the bands. I think D-Ext is the only one checked on mine. Never had any issues. Speedtests constantly come in at over 900mbps (usually 920-930), and this is with a PC testing through an adapter, so there's definitely no interference happening for me.

Welp, they came out today and installed... Pulling 940/35ish as designed which is good... But he only had the Hitron en2251 with him and insisted that's all they have (he is wrong, he also is an independent contractor and not spectrum)... Was hoping for the TC4400 which has the dual WAN and lets me get to the GUI, which this Hitron does not... Speed is great, but I just ordered for pickup an SB8200... The Hitron has a puma 7 chipset, f that, never again do I want an intel chipset modem.... SB8200 will give me dual WAN and UI also...

Oh, and my router wouldn't pull an IP from DHCP from the modem, and the guy wouldn't even wait around for me to make sure it did, said his handheld says internet is fine so he is leaving! a reboot of my rt-ax88u fixed it, but what a shirt experience... he also left my box outside the house a hot mess

 

[njhorn]

I've never fiddled with the checkmarks on the bands. I think D-Ext is the only one checked on mine. Never had any issues. Speedtests constantly come in at over 900mbps (usually 920-930), and this is with a PC testing through an adapter, so there's definitely no interference happening for me.

Dumped that Hitron quickly for an Arris SB8200 . Here are the signals Spectrum is using in case wondering... I was freaked out about all those correctable errors on channel 33 until I found out that is OFDM and normal per this link... https://www.dslreports.com/forum/r3...unt-of-Corrected-Errors-on-Downstream-Channel

Looks like I should be plenty safe to let moca 2.5 go full speed at 3500, I'll change it back tomorrow... Going to let this work a few days to ensure everything is good, then enable lan aggregation from the modem to my router and my router to my Synology nas as well... I have docker running 30 minute interval speetests with data graphed in grafana, I doubt I see a difference, but will be nice to know its there .

Speedtests are consistently 930-940 and 35-40 up, and usenet downloads (linux iso's of course?) are steady at 95-100MB/s (760-800Mbps)... In fact I've now throttled them down to about 75 to ensure when downloads are going that things like zoom calls don't get hurt... I know I could do qos for that, but that's a project for another day

 

[mr570]

I'm also curious about Mark's question about the CM600 cable modem. I have the same device and while I don't plan on getting more than 100mbps any time soon, I'd like to know it can handle speeds as advertised. Anyone know off hand?

 

[njhorn]

I'm also curious about Mark's question about the CM600 cable modem. I have the same device and while I don't plan on getting more than 100mbps any time soon, I'd like to know it can handle speeds as advertised. Anyone know off hand?

I was able to get 600Mbps on a CM600 on spectrum

 

[njhorn]

Hey there,

Recently I helped a family member with his new Google Nest Wifi (yes, he wanted easy and never touch). During this time we were talking about him having Coax already ran to the various rooms and possibly use MOCA for that.

Awhile ago, Best Buy sold him a Arris SB8200 Cable Modem. That modem is a DOCSIS 3.1 Cable Modem. I know the frequencies of those cable modems could collide with MOCA, but ... based on today (using Comcast as provider) would they really? Also, is it possible to tell the SB8200 which frequencies to use?

Side Question .. I have a Netgear CM600 Cable Modem. That is a DOCSIS 3.0 cable modem, and it works great with my MOCA network. The advertising for that Modem says 960 MB (just under GB speeds). The specs say for a 400 Mb/s data plan. Real work testing puts it at 275 Mb/s (roughly). Why are these numbers so wildly off?

Also, if my plan goes above 275 Mb/s, I would look to get the CM1000 Cable Modem (DOCSIS3.1), same question as the start .. colliding with MOCA.

Thanks!
Mark

im on spectrum and just got gigabit on docsis 3.1. No issues with moca 2.5. Spectrum using channels in 500-700hz range