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New House - Frequent Internet Drops and Slowdowns

New Poster

New House - Frequent Internet Drops and Slowdowns

I am having frequent internet connection issues in the house we moved into 2 months ago.  The line from Comcast / Xfinity is buried in the yard, and connected to the side of the house.  I have 150 down / 10 up.  I have a new Motorola MB8600 I bought when we moved into the house.  When first hooked up (over the phone with Comcast tech support), it seemed to work pretty well, but very quickly noticed that I get a lot of slowdowns (Speedtest will give me 10-40 Mbps instead of the usual 125+ Mbps I get when it's working fine), and outages where it seems like the modem loses its connection to Comcast (often the lights indicate it's rebooting itself).  In minutes it's usually back online, sometimes slow as above, sometimes full speed.  It seems to be worse as the day goes on.  I work from home - and today it was rock solid from the time I sat down for the next few hours, then it started failing again.  I called yesterday and they told me the problem was with my modem.  Since the thing is basically brand new and the problem is sporadic, I am skeptical of that.  I did login to the modem UI to look at that info and see a bunch of stuff I don't fully understand - here's the connection tab:

Startup Sequence    
   Startup Step Status Comment

  
   Acquire Downstream Channel 603000000 Hz Locked
  
   Upstream Connection OK Operational
  
   Boot State OK Operational

  
   Configuration File OK  
  
   Security Enabled BPI+
  



   Connection Status    
   System Up Time 0 days 00h:07m:25s  
  
   Network Access Allowed  
  



   Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (d Corrected Uncorrected    1 Locked QAM256 21 603.0 -0.3 39.5 312160 1144562    2 Locked QAM256 1 471.0 3.3 41.4 544732 1575518    3 Locked QAM256 2 477.0 3.2 41.1 542160 1615630    4 Locked QAM256 3 483.0 2.9 41.1 539023 1649048    5 Locked QAM256 4 489.0 2.2 40.6 539637 1694198    6 Locked QAM256 5 495.0 2.7 41.1 536913 1729917    7 Locked QAM256 6 507.0 1.4 40.4 539651 1800634    8 Locked QAM256 7 513.0 1.9 40.8 535212 1839430    9 Locked QAM256 8 519.0 1.9 40.7 540464 1876427    10 Locked QAM256 9 525.0 1.1 40.5 538352 1877302    11 Locked QAM256 10 531.0 1.3 40.4 537621 1906228    12 Locked QAM256 11 537.0 1.8 40.6 202392 729734    13 Locked QAM256 12 543.0 1.1 40.2 539115 1944250    14 Locked QAM256 13 555.0 1.3 40.5 348447 1254612    15 Locked QAM256 14 561.0 1.5 40.5 358058 1358297    16 Locked QAM256 15 567.0 0.6 40.1 544681 2022881    17 Locked QAM256 16 573.0 1.2 40.2 535134 1983895    18 Locked QAM256 17 579.0 0.7 40.0 222157 819464    19 Locked QAM256 18 585.0 0.5 40.0 420334 1592577    20 Locked QAM256 19 591.0 0.3 39.7 548697 2050025    21 Locked QAM256 20 597.0 0.1 39.7 547717 2058773    22 Locked QAM256 22 609.0 -1.3 39.0 354852 1321566    23 Locked QAM256 23 615.0 -0.5 39.3 218165 820970    24 Locked QAM256 24 621.0 -0.9 39.3 523919 2002340    25 Locked QAM256 25 627.0 -1.3 39.1 220775 842181    26 Locked QAM256 26 633.0 -1.7 38.7 205354 784544    27 Locked QAM256 27 639.0 -1.3 39.1 338548 1278239    28 Locked QAM256 28 645.0 -2.5 38.3 377654 1491152    29 Locked QAM256 29 651.0 -2.5 38.3 343194 1358082    30 Locked QAM256 30 657.0 -2.9 38.1 303101 1221507    31 Locked QAM256 31 663.0 -3.5 37.6 354805 1390867    32 Locked QAM256 32 669.0 -3.8 37.5 220421 862064    33 Locked OFDM PLC 159 690.0 -3.0 11.6 10165599 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 35.8 34.0    2 Locked SC-QAM 2 5120 29.4 33.8    3 Locked SC-QAM 3 5120 23.0 32.5



   Downstream Frequency Setting    
   Downstream Frequency Select   
  



   LAG Enable/Disable    
   LAG(Link Aggregation Group, or Ethernet Port Bonding)  
New Poster

Re: New House - Frequent Internet Drops and Slowdowns

I'm experiencing the same issues. I've been on several times with comcast support and they are sending a tech out tomorrow. Their support has been frustrating as I don't think they listen or know what they are looking at. 

New Poster

Re: New House - Frequent Internet Drops and Slowdowns

Thanks for the reply - did the tech fix it?  What was wrong?

My tech is coming Saturday morning - I'll post back with whatever they tell me.

New Poster

Re: New House - Frequent Internet Drops and Slowdowns

Latest log looks particularly grim...  Problem still ongoing.  Worth noting that I had a couple of hiccups this morning, then it started with a vengance about 11:30 AM.  Last night it cleared up around 5:30 PM after failing all afternoon.  We were able to watch streaming movies with no interruption, which would have been impossible in the afternoon.  I can't wrap my head around why the problem is worse during a certain time of day, but it sure seems to be.

 

Log  
  
    Time    Priority    Description      10:08:43
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     11:54:32
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:05:11
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:06:31
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:08:52
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:09:11
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:10:24
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:10:41
Thu Sep 5 2019
  Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:14:22
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:14:42
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:15:35
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:15:55
Thu Sep 5 2019
  Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:16:36
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:17:16
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:18:15
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:18:35
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:19:15
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:19:55
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:20:15
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:20:35
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:20:55
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:21:20
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:22:14
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:23:09
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:23:27
Thu Sep 5 2019
  Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:23:28
Thu Sep 5 2019
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;     12:26:32
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;     Time Not Established   Notice (6)   Honoring MDD; IP provisioning mode = IPv6     12:28:31
Thu Sep 5 2019
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;     12:29:14
Thu Sep 5 2019
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:4f:49:af;CMTS-MAC=00:9e:1e:59:4d:cb;CM-QOS=1.1;CM-VER=3.1;
New Poster

Re: New House - Frequent Internet Drops and Slowdowns

I finally thought to call Motorola's support line.  My modem is a MB8600 by the way (I had erroneously typed SB8600 in the original post).  They very quickly told me that the T3 and T4 errors are prevalent in my logs are indicitave of signal degradation (T3) and total signal loss (T4).  He said that's on my provider to isolate / fix.  He also suggested that I take screenshots of the logs to show the technician when he comes out since they will likely reset the modem and clear out the log history.  Also, there is no way to write the log out to a file.

 

All of this is exactly what I suspected and tried to explain to Xfinity tech support over the phone twice.  I was told by them that the problem was with my modem, and that I should consider replacing it with Xfinity's modem that I could lease from them.  Also they told me the onsite technician will cost me $70, regardless of where the problem is.

 

This is beyond frustrating - I feel like Xfinity has left me to solve this myself.  I am not optimistic about the technician on Saturday but at least I can provide him specifics about the problem that I've had to figure out myself.  


Why Xfinity couldn't look at my modem history and see that it keeps disconnecting and reconnecting, and at least agree that there is some kind of a signal problem is beyond me.  In any case, I'll post back here after the tech comes.

New Poster

Re: New House - Frequent Internet Drops and Slowdowns

Update - it looks like my issue may be resolved.  Short version is that an Xfinity line crew replaced the "feeder" line at the end of the block, which was apparently bad.

I had an Xfinity tech come to the house on Saturday and he immediately cut and replaced all of the coax connectors in the house, then made some "adjustments" to the junction box that the line from the house comes from.  He said he thought it should fix it, but I showed him the cable modem was still getting T3 errors.  Not only that, my speed test results had gone down from what I was getting when the connection was good (125 Mbps) to 80-90 Mbps tops.  He tinkered some more and then told me he escalated the call to get a line crew (not sure if that's the term he used) out to look at the lines in the neighborhood.  He left and told me they'd be out in the next few days.  From that point on, I had pretty consistent T3 and T4 errors, disconnects, and overall dismal internet performance.  I think it was worse than before he came.  I was pretty pessimistic on a resolution to the problem.

 

Yesterday, the internet went out for about 15 minutes (it usually would come back within 5 mins or so), so I went out to walk the dog.  On the walk, I got an automated call saying that my issue with the lines "has been resolved".  Incredulous, I walked around the corner at the end of the block and to my surprise found an Xfinity truck with a guy sitting inside.  I tapped on his window and soon discovered that he was the guy who was dispached for my issue, and he told me that he had replaced the "feeder" line to my block (or something like that) with a temporary cable, and that they'd come out and replace it with a permanent one soon.  He looked at his laptop and said he could tell that my modem had a good signal now, and that I should be set.  I walked home skeptical but encouraged.  Got home and didn't have any issues at all.  Internet was solid all afternoon and evening.  No errors at all in the modem logs.  It's not been about 20 hours since *anything* has been logged on the modem, and the internet connection is still solid.  The only issue remaining is that my speedtest results are still below 150 Mbps.  I'm only getting about 100-110 down, but at least it's stable.

So I'm cautiously optimistic that I'm good for now.  I'm not sure about the download speed - the modem is rated for gigabit and I'm paying for only 150 Mbps.  I have an older router I've been considering replacing anyway, so I may do that soon and see if it makes any difference before complaning about the speed.  In the meantime, I'll just be happy to be stable and have reliable internet.

I'm still pretty annoyed that this clear Xfinity issue required so much effort on my part for them to address.  If the line tech could tell me looking at the signal strength of my cable modem from his laptop that my issue had been resolved, then surely someone could have determined that it was bad before then.  Instead, tech support told me repeatedly that the issue was my modem, and tried to get me to lease one from Xfinity.  That would clearly not have solved the problem.

Anyway, I'm tired of screwing with this, but thought I'd close this out with the conclusion.  I'll post back here when and if I get a new modem and/or the speed changes.