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CM1150V Upstream Channel Problem with Xfinity
I purchased a CM1150V to replace an Xfinity (Arris) XB6. The XB6 had been in place, running in bridge mode, for 2 months. It showed (4) upstream channels with good power levels, (31+OFDM) downstre...
An Xfinity tech was out today. He found a noise block filter at the pole. No idea when or why it was installed. That was blocking the two lower frequency channels.
A noise block filter had previously been ruled out, because the Xfinity-supplied Arris XB6 was reporting all (4) channels locked. So I now question the veracity of the Arris XB6 status page. All other modems tested (CM1150V, Arris TM722G, Arris SBV3202) were unable to lock the channels with that filter in place. So I don't think the Arris XB6 was actually locking those channels either, even though it said it was.
Once the tech removed the noise block filter at the pole, the CM1150V immediately locked all (4) channels. The constant T3/T4 errors are gone as well. No problems with the CM1150V, the upstream issue was all from a previous Xfinity/Comcast tech installing that noise block filter at the tap.
Thanks to vkdelta for help and supporting information, which helped me explain/prove the problem to Xfinity so they would come fix it!
You might try another same model cablemodem to see if the problem continues. Could be bad HW as well. Try a CM1100 modem and see if it does the same thing. If it does, then both NG and CC need to address this.
FURRYe38 wrote:
You might try another same model cablemodem to see if the problem continues. Could be bad HW as well. Try a CM1100 modem and see if it does the same thing.
Already tried a second CM1150V, and it behaves the same. Also tried an Arris SBV3202 -- it does not indicate any service problems. That implies a CM1150V firmware problem, erroneously flashing the LED when no problem exists, but I don't have enough data to conclusively prove that. I'd use the Arris SBV3202, but it isn't Comcast-approved for future gigabit service which is why I went with the CM1150V -- but am keeping the SBV3202 as a backup / emergency spare. The CM1100 doesn't support voice, so that doesn't fit my needs. Having already purchased (3) modems and following extensive testing, logging, resets, etc. via tickets with both Netgear and Comcast, I feel like I've already gone further than any customer should have to go.
FURRYe38 wrote:
If it does, then both NG and CC need to address this.
I agree, both Netgear and Comcast should be working together to isolate and correct whatever the problem is. Either the CM1150V is accurately detecting a partial service issue at Comcast and correctly flashing the Upstream LED (but failing to display that status in the GUI), *or* everything is just fine at Comcast and the CM1150V is erroneously flashing the LED.
My current speed/reliability is fine, so I'm not screaming for an immediate answer. Just want to know that someone is working on it, and that it will eventually be addressed. Obviously something is wrong, with either the service or the status reporting, and it would be nice to know that someone cares about fixing that problem even if speed/reliability isn't impacted.
FURRYe38 wrote:
Best way to let NG know is to file a support ticket.
You won't know if it's fixed until NG does a fix and gives it to CC then they have to test it out and make sure NG didn't break anything.
Good Luck.
Not sure if you read my post -- as I mentioned earlier in this thread, I opened tickets with Comcast and Netgear. Both ran me through all the "basic" troubleshooting (power cycle, check levels, check provisioning file, factory reset, yada yada yada) -- and then just appeared to lose all interest when those basic steps turned up nothing to explain the issue. NG ticket #41178878; I never heard back after my last follow-up.
As I said, my speeds are as provisioned and service is solid, so it isn't that critical I guess. Still, it's a $250 piece of equipment so I would eventually like a resolution. Its sort of like a car with a temp gauge that says everything's fine, but the overtemp light is flashing. Which is correct? Having the dealer just tell me to "ignore the flashing light as long as its still running" would not satisfy me. :-)
You'll have to keep in contact with NG and CC. Hopefully something will get fixed. It won't be quick I presume.
If the modem is working accept for this one thing, then it may not be critical. If not, then return the modem and use something else and come back to this later on.
Good Luck.