Started Unicast Maintenance Ranging - No Response received (Daily internet service drops)

[AC2k]

Modem: Motorola MB8600

I also have an Arris MB6183 i can try if anyone thinks that might work better?

I get this every day and my internet drops.  Already had a tech out who basically alluded that there was nothing that could be done because of how the cable heats up when it is hot outside, combined with possibly poor wiring in my building.  Does this sound right?  There's really nothing I can do to prevent these small outages? (It goes down for a few seconds then comes back, but knocks me off my employer's VPN when it does and kills my IP phone calls.  I think my colleagues are getting tired of me always dropping out of meetings.)

This has been an issue since I've lived at the address (2+ years).  For a while I had an amp with active return on the line and didn't experience any issues for a long time. Then these short drop-outs started occurring about a month ago, which is why I had the tech come out.  I haven't put the amp back on the line, but the dropouts were occurring even I did have it connected.

I have NO SPLITTERS on the line at all.  It goes from the wall plate (which the tech also checked behind and said it was fine) straight to the modem.  Switching coax cables doesn't help.

Tech said my signal levels were OK.

(Address info removed from the log for public posting)

Event Log

Log

Time    Priority    Description      09:51:13 Fri Aug 7 2020   Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;     09:54:04 Fri Aug 7 2020   Critical (3)   Unicast Ranging Received Abort Response - Re-initializing MAC;     09:54:09 Fri Aug 7 2020   Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;     09:54:34 Fri Aug 7 2020   Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;

Startup Step	Status	Comment
Acquire Downstream Channel	561000000 Hz	Locked
Upstream Connection	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+

Connection Status

System Up Time 4 days 16h:59m:43s         Network Access Allowed

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected    1 Locked QAM256 25 585.0 4.5 40.4 2788 3324    2 Locked QAM256 9 483.0 3.9 40.2 3699 2943    3 Locked QAM256 10 489.0 4.1 40.2 3576 3168    4 Locked QAM256 11 495.0 4.2 40.2 3769 3606    5 Locked QAM256 12 507.0 4.5 40.4 3685 3671    6 Locked QAM256 13 513.0 4.6 40.3 3402 3347    7 Locked QAM256 14 519.0 4.6 40.3 3474 3357    8 Locked QAM256 15 525.0 4.5 40.4 3289 2952    9 Locked QAM256 16 531.0 4.5 40.4 3417 3380    10 Locked QAM256 17 537.0 4.6 40.5 3186 3187    11 Locked QAM256 18 543.0 4.6 40.5 3310 3528    12 Locked QAM256 19 549.0 4.3 40.4 3077 3178    13 Locked QAM256 20 555.0 4.3 40.6 3295 3625    14 Locked QAM256 21 561.0 4.1 40.7 3045 3236    15 Locked QAM256 22 567.0 4.0 40.5 3490 3860    16 Locked QAM256 23 573.0 4.0 40.4 2976 3621    17 Locked QAM256 24 579.0 4.4 40.5 3076 4257    18 Locked QAM256 26 591.0 4.6 40.5 2737 3472    19 Locked QAM256 27 597.0 4.7 40.6 2509 2776    20 Locked QAM256 28 603.0 4.6 40.5 2656 3236    21 Locked QAM256 29 609.0 4.3 40.4 2446 3036    22 Locked QAM256 30 615.0 4.1 40.3 2635 3584    23 Locked QAM256 31 621.0 4.3 40.4 2368 3185    24 Locked QAM256 32 627.0 4.5 40.5 2179 3155    25 Locked QAM256 33 633.0 4.7 40.3 1984 2513    26 Locked QAM256 34 639.0 4.9 40.5 1893 2402    27 Locked QAM256 35 645.0 5.5 40.6 1833 2312    28 Locked QAM256 36 651.0 5.7 40.5 1942 2112    29 Locked QAM256 37 657.0 5.8 40.5 1793 1906    30 Locked QAM256 38 663.0 5.6 40.3 1550 1679    31 Locked QAM256 39 669.0 5.5 40.4 1597 1608    32 Locked QAM256 40 675.0 5.0 40.0 1636 1552    33 Locked OFDM PLC 159 690.0 6.3 39.2 1197 0

Upstream Bonded Channels

Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)    1 Locked SC-QAM 1 5120 16.2 46.0    2 Locked SC-QAM 2 5120 22.7 46.5    3 Locked SC-QAM 3 5120 29.2 47.0    4 Locked SC-QAM 4 5120 35.7 48.0    5 Locked SC-QAM 5 1280 41.2 48.5

[AC2k]

I do see that my downstream SNRs are too high, meaning too much noise on the line(?).  I don't think there is anything I can do to affect that though, is there?  Are some modems more susceptible to noise like this than others?

[EG]

Nope. The SNR can never be "too high". Higher is better ! Higher means less noise, not more noise.

If anything, the upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

[AC2k]

Higher is better (SNR)... ahhh yes... my bad.  

Going by the "Internet Troubleshooting Tips" post, my upstream levels are right on the line, so I suspect maybe that is indeed the issue.  Maybe I will throw the amp back on the line which should pull those down quite a bit.  The tech that came out indicated those levels should be ok, but clearly I am still having the same issue.

And, as I mentioned in my post, I have 0 splitters on the line.  The tech replaced the one I had on there, but in the days that followed I saw the upstream levels getting up to 55, so I removed the splitter, which seems to keep them right under or at  50.

Other than adding the amp I'm not sure what else I can do.  I've already had a tech out here and I have no splitters to remove. 

[EG]

I would try the amp !

As an FYI, bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.

Good luck with it !

[AC2k]

Thanks!  That is good to know.  Sounds like I'll have to call in again if the amp doesn't help me.

I wish it were easier to contact comcast for service.  I just end up in a never-ending loop with the chatbot and when I call in I always have to re-start my modem, wait ten minutes for a message that never comes, call back in, restart my modem again, wait another ten minutes for a message that never comes, then call back in again, then at that point I get added to the queue to be put on hold for the next available representative.  It's such a waste of my time.

But that is a completely separate issue, of course.

[EG]

Sorry. I feel your pain ! I don't work for them or make policy.

[AC2k]

On the plus side, once I do get through to a rep they are generally friendly, sympathetic, and seem like they want to do whatever they can to help.

Comcast just needs to adjust their chatbot and IVR.  (sigh)

[AC2k]

Looks like the amp has made my downstream levels too high and my upstream levels too low.  Should I try a less-powerful amp maybe?

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected    1 Locked QAM256 17 537.0 18.3 40.1 0 0    2 Locked QAM256 1 423.0 17.7 40.2 0 0    3 Locked QAM256 2 435.0 17.8 40.0 0 0    4 Locked QAM256 3 447.0 17.6 40.0 0 0    5 Locked QAM256 4 453.0 17.5 39.8 0 0    6 Locked QAM256 5 459.0 17.4 39.7 0 0    7 Locked QAM256 6 465.0 17.3 39.6 0 0    8 Locked QAM256 7 471.0 17.5 39.6 0 0    9 Locked QAM256 8 477.0 17.8 39.8 0 0    10 Locked QAM256 9 483.0 18.1 39.8 0 0    11 Locked QAM256 10 489.0 18.3 39.6 0 0    12 Locked QAM256 11 495.0 18.3 39.8 0 0    13 Locked QAM256 12 507.0 18.4 39.8 0 0    14 Locked QAM256 13 513.0 18.5 39.8 0 0    15 Locked QAM256 14 519.0 18.4 39.9 0 0    16 Locked QAM256 15 525.0 18.3 39.9 0 0    17 Locked QAM256 16 531.0 18.2 39.9 0 0    18 Locked QAM256 18 543.0 18.3 40.1 0 0    19 Locked QAM256 19 549.0 18.0 40.0 0 0    20 Locked QAM256 20 555.0 18.0 40.1 0 0    21 Locked QAM256 21 561.0 18.0 40.3 0 0    22 Locked QAM256 22 567.0 18.1 40.1 0 0    23 Locked QAM256 23 573.0 18.1 40.1 0 0    24 Locked QAM256 24 579.0 18.5 40.1 0 0    25 Locked QAM256 25 585.0 18.4 40.0 0 0    26 Locked QAM256 26 591.0 18.5 40.1 0 0    27 Locked QAM256 27 597.0 18.6 40.0 0 0    28 Locked QAM256 28 603.0 18.3 40.1 0 0    29 Locked QAM256 29 609.0 17.9 40.0 0 0    30 Locked QAM256 30 615.0 17.7 40.0 0 0    31 Locked QAM256 31 621.0 17.7 39.9 0 0    32 Locked QAM256 32 627.0 17.8 39.7 0 0    33 Locked OFDM PLC 159 690.0 20.1 38.8 0 0

Upstream Bonded Channels

Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)    1 Locked SC-QAM 1 5120 16.2 31.5    2 Locked SC-QAM 2 5120 22.7 31.5    3 Locked SC-QAM 3 5120 29.2 32.0    4 Locked SC-QAM 4 5120 35.7 32.0    5 Locked SC-QAM 5 1280 41.2 33.0

[AC2k]

Had to remove the amp.  It went crazy with the amp on the line.  I ordered an amp with way less gain but it won't get here for a while.  I'll report back after that with status in case anyone else is having a similar issue and trying to solve it a similar way.

I'm not exactly sure what to say to comcast when/if I do end up contacting them again, other than "already had a tech out.  Still doesn't work."  I'm not sure what actually triggers the escalation process.  It's a tough one to solve because of course the problem never manifests itself when a tech is actually here.

[AC2k]

Got the new amp which is 7db.  Did not fix the problem, but now my internet only drops 1-2 times per day as opposed to 10+ times per day.  It's an improvement, but not a fix, and I still see the same errors coming through the modem log when the problem occurs.

Oh yes, and I also replaced the modem.  And the cabling. 

I think I'll just move.  I can only get Xfinity in my current lcoation but (another provider) is available almost everywhere else in the same city.  It's probably easier than trying to get this fixed.

[AC2k]

So I was able to get back in touch with Xfinity support and tried to ask for a next-support-tier escalation, since the tech couldn't find anything wrong.  They basically told me no further troubleshooting could be done unless I rent a modem from Xfinity, even though I've treid 3 different supposedly "xfinity-certified" modems.

$14 a month for a modem rental when a good modem costs about $70 is highway robbery. 

So they are sending me a modem.

I have 0 expectation that this will make any difference.  The problem is clearly not on my side of the wall.  I don't know how to get someone to listen to me.  The guy kept talking about WiFi and how I'll be able to see what devices are conencted to Wifi (with teh Xfinity Modem) even though I said multiple times I'm not using WiFi.

But I guess it is policy to not troubleshoot further unless you get your modem from them, so I guess I have to pay more money to prove that the problem is not with the modems.

[AC2k]

Have installed the Xfinity gateway to replace my Arris modem.  (Xfinity modem is also made by Arris, apparently).

Can't figure out how to see the error log, but the signal levels do look slightly better.  About +3db for downstream and about +45db for upstream.  No amp or antyhing on the line now - I used the xfinity-provided cable to conect directly from the wall-plate to the gateway device.

I'm already seeing the codeword errors, but service has not dropepd yet.  It's only been a few hours though.

One thing I will say is that this gateway device is excruciatingly slow to log in to and navigate around.  Not sure if that means anything.  It does eventualy bring up the requested pages, but it's not snappy like my personally owned modems were.  I have enough time to go pour a cup of coffee while i'm waiting for the darned page to load. I'm plugging my laptop directly into the gateway to manage it, so its not something else on my network affecting the response time.

I'll be calling Xfiity back as soon as my conenction starts dropping again, but now I can't find the actual errors to relay to anyone.

[AC2k]

As expected, no change at all with the Xdfinity-provided equipment.  Internet still drops, and I can see thousands of uncorrectible codewords in the network status page.

Called back in.  Talked to a woman for what seemed like a long time (maybe 20-30 minutes?) who ran me through the modem reset nonsense again.

She ccouldn't help.  Tranferred me to a guy on the other side of the country who seemed very knwoedgeable and very willing to help.  He didn't know I had already talked to someone so of course I had to go through the whole spiel again.  He seemed genunely interested in helping but said he could not see my modem information and he needed to get someone on the line with us in my state.

Then I got put back into the regular call queue.  The next rep who picked up (after another period of time on hold) also had no idea I'd already talked to two other people.  She said "Oh I'm looking up your account" and then I got some hold music, then an extremely loud buzzing, then hung up.

I called back and then started at squarte one with "we're resetting your modem."

My tolerance level has been reached.  I will be cancelling my Xfinity service. I have wasted enough of my time and money on this nonsense.