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SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Frequent Visitor

SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

So, I own my own modem. I have for years and have upgraded as devices have reached their EOL or reviews for Xfinity approved modems state you get the full speeds you’re paying for. I had an SB8200 Modem for about six months and started having significant problems in November. The week before Thanksgiving I kept noticing the connection was dropping and coming back up later, but I figured it may have been an intermittent issue that would eventually clear up. Then the week of Thanksgiving things got worse as the week progressed to the point the Modem might stay up 15 minutes before rebooting. During that initial week, I contacted Comcast Chat and asked was I in maintenance mode or something (sidenote: in the past with my sb6190 someone was doing maintenance and left my modem on the maintenance server.[it took 5 separate calls to get to a tech who knew and understood exactly what was going on] I'm on the Extreme tier so my speeds dropped in that incident to levels of 5 to 10 down and 5 to 10 up).

So, I figured maybe someone was going through doing maintenance again. The tech I spoke with on the chat said he was switching me to another server for a more stable connection. It seemed to work for a while too as my connection stayed up for the rest of that evening. However, the next morning it had dropped offline again. I contacted Comcast chat again, and of course, they wanted to run through that script of troubleshooting steps and I asked the rep could I just get my problem escalated to someone else as it was going on two weeks with a near nonexistent internet connection. He didn’t argue with me and escalated my case. I got a couple of calls from the higher support tier while I was at work but couldn’t respond. My connection was solid for two days so I figured they had found something and fixed it. But eventually, things digressed again with the repeated modem reboots. I got fed up and called that week of Thanksgiving on Friday evening complaining. Of course, I got a tech who didn’t want to do her job and the first thing out her mouth was, “you don’t need a tech to come out, it’s not our problem it’s the modem and since you own it that’s your responsibility” Note she hadn’t tried or checked anything.

 

Now please note I pay for the insurance on my lines so I never have to worry about paying for a tech to come out[if the need ever arises]. After having a come to Jesus conversation with this tech she quickly scheduled a tech to come out the next day 12/1. I explained to him what had been happening and that one of the messages in the event log said 16 consecutive T3 timeouts and a bunch of Dynamic Range window violations. I let him know I researched online and found an Xfinity forum where someone had the exact same problem and said when their technician came out it was found the upload signal was extremely too high and that was the cause of constant modem reboots. Someone explained the dynamic range window violation was the ranging of the upload signal going out of spec. I even took him to the modem’s status page and he looked at my numbers and said “yea those could be a lot better. I’ll run a new line and then we’ll go from there” The tech took his time and even had to go to the neighbor’s house behind me in order to get to the pole properly. After the line change, my levels improved significantly and my speeds even got better than what I had been previously experiencing. I was usually about 150 down/ 20 up and I went to about 230 down/ 25 up. My connection stayed solid for a couple of hours (approx. 5) and then the rebooting of the modem started up again. Except for this time, it was less frequent. Since I had a Warranty on my modem (note only 6 months old) with Best Buy I just took it in for exchange for a new one the next day.

I returned home, called Comcast to get it set up and eventually got online. I noticed my event log on this brand new off the shelf modem stayed clean the entire day. No T3 or T4 timeouts of any kind, no dynamic range window violations, and connection stayed rock solid entire day. Next morning the modem was flashing again and offline. I immediately called Comcast and they said, “We need to have a tech come out again.” I was scheduled for that weekend 12/8. It was a severely cold weekend and raining. The tech came out in his rain gear and even had the courtesy to put the little foot booties on before he stepped in the house. I explained to him what had been happening and he told me he was going to check a couple of things. He returned later and said “I’ve checked your lines and everything looks good. The previous tech did the run right and your levels are great. I even looked inside the box and there’s no water and everything is clean. I suspected water was in the line, but everything was completely dry.” He showed me my levels were 11’s or close to 11 across the board on his phone. He then said “I can verify nothing is wrong with your lines or your modem. From what you described to me, he said, it sounds like there’s a problem in the neighborhood node or further down the line. They’re (Comcast) particular about who does that kind of maintenance and I wish I could take a look but I haven’t been trained for that.” He then said, “I’ll have to get in touch with my supervisor and a bucket truck may have to come out to look and hopefully fix the issue at the node if it’s there”.

I explained to him in the past I had an issue with speeds and was told it was noise on the line and they increased the frequency and it stopped. He said “Yea for that issue it could be a number of things. It’s not necessarily you or your wiring but it could be someone else’s connection causing it. He said the hookups at the pole can have 6 to 8 connections meeting so there are opportunities for crosstalk etc.” He then asked me “With your current issue does it seem like your connection pauses but isn’t offline?” I told him yes, I’ve had moments where it was like the internet just stopped for a moment, but I checked the modem and it was fully connected and no flashing lights. He then said “yea that sounds like water is in the lines somewhere. What happens when water is in the line in say a node box the signal can refract right back down the line.”  He then said, “And unless we start getting complaints from others in the neighborhood everything looks good on our end instead of an outage ticket being placed.” I told him that might be why things seem to be so much worse when it rains. He said, “Yea and when things dry out you probably have next to no issues”. He apologized that he couldn’t do more but said he knew some of the guys that typically performed work on the nodes and would contact the guy from my area.

Well going on week 5 still having the same issues. Still trying to figure out the issue and if anything cloud be done on my end I looked up my cable modem model and issues on Comcast. I found many people have had a similar problem. I even found a forum that stated the modem doesn’t pull in the proper firmware and you have to reset it in order for it to download the firmware file and apply it. One replier said they did so an all connection issues stopped. I figured why not. I did the reset and saw the listing of the firmware download, but then it said it failed because the firmware was corrupt. I’m currently on software version D31CM-PEREGRINE-1.0.1.0-GA-04-NOSH.

 

I just need some help to get a solid connection again or I’m just going to have to leave Comcast and find service somewhere else. Though choices are very limited. I thought about getting another new modem, but as I researched those recommended on the Xfinity My Device Info page I saw many of them had just as many issues. Does Comcast have bad firmware that they keep pushing out? What the heck is really going on? And if the SB8200 isn’t compatible, for the love of God remove it from the list of compatible devices.Pic1.JPGStatus_1

 

Pic2.JPGStatus_2

 

Pic3.JPGStatus_3

 

ProductInfo.JPG

 

Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Also below are the Event Logs from earlier in the morning. The last two are the logs I took as my connection repeatedly went up and down while trying to post this. I even called customer service and got fed up because the rep wanted to take me through troubleshooting steps with an ethernet cable.EventLog_1.JPGEvent Log 1

 

EventLog_2.JPGEvent Log 2

 

EventLog_3.JPGEvent Log 3

 

EventLog_4.JPGEvent Log 4

 

EventLog_5.JPGEvent Log 5

 

EventLog_6.JPGEvent Log 6

 

EventLog_7.JPGEvent Log 7

 

Expert

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Can't see your pics. Since you are a new poster, they likely need to be approved by a Forum Admin. Or you may need to make a minimum number of posts.

You could try hosting them at one of those free third-party pic hosting sites and post the link to them here.



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Ok Sorry about that. Here's a link to them in an album

https://1drv.ms/a/s!AkJYVah1KmnrxHkdp0_OsqbrP0aP 

It's via OneDrive

Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Well, a tech is coming out for the 3rd time in the morning. We'll see what transpires from this. I'm praying they actually fix the issue.

 

 

Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Well this morning I woke up to the modem actually being on and not flashing or offline. I checked the status page and it had been up, according to the timer, for 11 hours and 8 minutes. I took it out of my network devices mix and hardwired it to a spare laptop. I performed a speed test and it was abismal but I heard a hopeful sound outside. It was the beeping of what sounded like a bucket truck backing up somewhere up the street. I kept checking the speeds every 10 to 15 minutes and it seemed they kept improving. That initial speedtest was VERY jittery but I noticied with each test things got smoother and speeds increased. It got to a point I was averaging about 90/95 Mbps down and 5/10 Mbps up. However I recently checked and speeds are ideal

https://www.speedtest.net/my-result/d/165715cb-c989-49ae-861d-05c1fa450253

 

My modem has been up 1hr 23 minutes and counting and no disconnects. I also noticed my event log no longer has the multiple T3 timeouts being produced

 

Now I'm just waiting on the tech to show up and give me the all clear and I think my issue has finally been resolved. Thank God.

Expert

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues


@kickguru wrote:

 

Now I'm just waiting on the tech to show up and give me the all clear and I think my issue has finally been resolved. Thank God.


Hopefully.

Keep us appraised of the situation. 


I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Well, I stand corrected. Everything was fine this morning. Then the disconnects started happening again. I just got through rebooting the modem to see how long it's going to last right now. I guess my only recourse is to just cancel service. The BBB is going to get an absolute kick out of this. At this point they're showing me they're never going to fix it nor do they care to. It's amazing I had an appointment and the tech never showed up but had a call sent saying they were outside at 8:15. The appointment was between 8a-10a. I waited by the door till 10:05a and nobody showed up.

Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Here's my current logs as of 4:28pm today 12/17/18

Connection

The status listed show the connection state of the cable modem. They are used by your service provider to evaluate the operation of the cable modem.

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 633000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK  
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed  

 
Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
29 Locked QAM256 633000000 Hz 8.5 dBmV 41.1 dB 738 0
1 Locked QAM256 465000000 Hz 7.7 dBmV 41.7 dB 0 0
2 Locked QAM256 471000000 Hz 8.3 dBmV 42.2 dB 0 0
3 Locked QAM256 477000000 Hz 8.7 dBmV 42.1 dB 0 0
4 Locked QAM256 483000000 Hz 8.8 dBmV 42.2 dB 0 0
5 Locked QAM256 489000000 Hz 9.2 dBmV 42.2 dB 0 0
6 Locked QAM256 495000000 Hz 9.1 dBmV 42.2 dB 0 0
7 Locked QAM256 501000000 Hz 9.5 dBmV 42.4 dB 0 0
8 Locked QAM256 507000000 Hz 9.7 dBmV 42.2 dB 5 0
9 Locked QAM256 513000000 Hz 10.5 dBmV 42.6 dB 8 29
10 Locked QAM256 519000000 Hz 9.8 dBmV 42.4 dB 0 0
11 Locked QAM256 525000000 Hz 9.6 dBmV 42.2 dB 0 0
12 Locked QAM256 531000000 Hz 9.1 dBmV 41.9 dB 0 0
13 Locked QAM256 537000000 Hz 9.3 dBmV 42.0 dB 0 0
14 Locked QAM256 543000000 Hz 9.0 dBmV 42.0 dB 0 0
15 Locked QAM256 549000000 Hz 9.2 dBmV 42.0 dB 0 0
16 Locked QAM256 555000000 Hz 8.7 dBmV 41.7 dB 0 0
17 Locked QAM256 561000000 Hz 9.1 dBmV 41.7 dB 0 0
18 Locked QAM256 567000000 Hz 8.9 dBmV 41.6 dB 0 0
19 Locked QAM256 573000000 Hz 9.1 dBmV 41.7 dB 0 0
20 Locked QAM256 579000000 Hz 9.1 dBmV 41.8 dB 0 0
21 Locked QAM256 585000000 Hz 9.1 dBmV 41.6 dB 0 0
22 Locked QAM256 591000000 Hz 9.0 dBmV 41.5 dB 0 0
23 Locked QAM256 597000000 Hz 8.8 dBmV 41.5 dB 0 0
24 Locked QAM256 603000000 Hz 8.7 dBmV 41.5 dB 0 0
25 Locked QAM256 609000000 Hz 8.9 dBmV 41.6 dB 0 0
26 Locked QAM256 615000000 Hz 9.0 dBmV 40.9 dB 0 0
27 Locked QAM256 621000000 Hz 9.0 dBmV 41.2 dB 0 0
28 Locked QAM256 627000000 Hz 8.8 dBmV 41.2 dB 0 0
30 Locked QAM256 639000000 Hz 8.5 dBmV 40.8 dB 0 0
31 Locked QAM256 645000000 Hz 8.7 dBmV 41.1 dB 0 0
32 Locked QAM256 651000000 Hz 8.7 dBmV 41.1 dB 0 0
159 Locked Other 702000000 Hz 11.5 dBmV 40.0 dB 67214 1

 
Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 1 Locked SC-QAM 36800000 Hz 6400000 Hz 38.8 dBmV
2 2 Locked SC-QAM 30400000 Hz 6400000 Hz 38.8 dBmV
3 3 Locked SC-QAM 24000000 Hz 6400000 Hz 38.8 dBmV

 

Current System Time: Mon Dec 17 16:27:34 2018

 

Event Log

The table below contains the log of events that the Not Available has detected. This log can be important to the service provider to help diagnose and correct problems, if any should occur.

Time Priority Description
1-1-1970, 0:0:43 Notice(6) "Honoring MDD; IP provisioning mode = IPv6"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 14:23:22 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 14:0:0 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:58:2 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:58:2 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:57:47 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:54:20 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:54:20 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:49:49 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:48:49 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:47:49 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:47:46 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:47:14 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:45:56 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:45:46 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:45:42 Critical(3) "Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:45:42 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:44:25 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:43:46 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 13:32:28 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:43:10 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:42:58 Critical(3) "Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:42:58 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:41:40 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:41:29 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:27:35 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:26:6 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:26:2 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:18:49 Critical(3) "16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:18:49 Critical(3) "Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:18:49 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:18:30 Critical(3) "16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:18:30 Critical(3) "Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:18:30 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:17:30 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:7:31 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 11:2:40 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:33 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 10:43:7 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 10:43:7 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 10:42:53 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=d4:ab:82:ff:62:19;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;"
12-17-2018, 10:42:53 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol 
Silver Problem Solver

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

I found the outage map, which was helpful for my issue.

https://www.xfinity.com/support/status-map/


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Expert

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

I had the SB8200 for nearly a year, it's been a pretty solid performer for the most part.

 

I noticed your downstream power levels have been pretty high. I don't know how cold it is where you live, but lower temperatures contribute to signals coming in too hot.

 

If there's an amplifier on your line, you might consider removing or bypassing it for the time being, or you might consider a signal attenuator to tone down the power (3 dB at least, maybe even 6 dB).

 

If this isn't feasible, I can go ahead and escalate your issue to a Comcast Specialist here for further assistance since you've had several tech visits already - you decide. 


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Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Thanks for that. I've checked the outage map in the past and its always said there's no issue. I'll keep checking it though. However https://downdetector.com/status/comcast-xfinity gives a very colorful look at the issues Comcast seems to be having. Makes me wonder has becoming the sole internet provider for so many locations become too big for one company to manage?

Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

I'm at a loss myself. The SB8200 had been fine for me until recently. It's fairly cold here. About 48 F here now and expected to be 43 tonight. (Feels colder since I'm near a lake area). Plus about 3 days or so of rain is coming according to the forecast. In the past though the colder it got the faster my connection was, probably due to keeping the lines cool. I don't think there's any kind of amplifier on my line. From what I can see it comes straight from the pole, to a grey Comcast box mounted on the house, and from that box to the coax in the house. Nothing in between, no splitters or anything.

 

Well I'm up for anything so escalation is fine by me. Otherwise it looks like dial-up is going to become a good friend of mine. It had been up about 6.5 hours today before these constant reboots started again.

 

There used to be a time where Comcast would say "hey this has happened and its affecting this and that" but nowadays its just complete silence. Or you're just ignored when you complain. Its sad when your in a city and Comcast is the sole provider, while others can't cross into certain parts of the municipality *sigh*

Silver Problem Solver

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues


@kickguru wrote:

Thanks for that. I've checked the outage map in the past and its always said there's no issue. I'll keep checking it though. However https://downdetector.com/status/comcast-xfinity gives a very colorful look at the issues Comcast seems to be having. Makes me wonder has becoming the sole internet provider for so many locations become too big for one company to manage?


Have you seen this:

https://www.xfinity.com/support/status/


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I am just a customer, volunteering my time to help other customers here in the Forums.
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Expert

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues


@kickguru wrote:

Well I'm up for anything so escalation is fine by me. Otherwise it looks like dial-up is going to become a good friend of mine. It had been up about 6.5 hours today before these constant reboots started again. 


Done, please make sure to check back as an official reply will be forthcoming. 


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Official Employee

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Hello kickguru. Thanks for posting about this on our Forum. Apologies for the lack of reliable service. I can assist with diagnosing and troubleshooting your intermittent connectivity issues. I'd like to start with polling the CMTS for real-time and historical RF signal reports from your modem. I can also check your local Node/Plant for any degradation or error reports. Please send me a private message and include your full name so I can access your equipment. 


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Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Just to update everyone, including ComcastJoeTru that I've been conversing with through private message. He had issues initially because my modem had jumped offline. I woke up the next morning and saw his message he couldn't perform the tests he wanted so I reset the modem and it stayed on most of the day 12/20. He told me my diagnostics were great and the only issue he could see was very high T3 timeouts and an out of spec Downstream Recieve Power level. Before this I had remembered there was Xfinity wi-fi so I used it for the small stuff I needed to do online. 

 

Then 12/21 and 12/22 things got horrible again. 12/21 the connection stayed up all day, no disconnects until late that evening. It jumped offline twice but got back on. Next day all heck seemed to break loose. My modem repeatedly kept jumping offline and back online. Sometimes staying a couple of minutes (10 or so) and jumping back off or 10 seconds and jumping back off. I was in the middle of trying to do some important things and the internet connection dropped again. I finally got fed up and went back to BestBuy. My plan was to exchange my Arris SB8200 in for a Netgear CM1000. I had read some forums on Netgear's site that there was a moment of issues with this modem and I believe the gateway version of it but a new firmware was released that cleared everything up. 

 

I figured it was worth a try to see what would happen. I got the modem activated and haven't had it go out yet. Here's the modem status logs and event log below

 

 
 
 
Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 633000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enable BPI+
IP Provisioning Mode Honor MDD IPv6 only

<tabindex=-1>Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 29 633000000 Hz 8.2 dBmV 41.6 dB 79555910 7513 26488
2 Locked QAM256 1 465000000 Hz 6.7 dBmV 42.7 dB 78151169 7109 25348
3 Locked QAM256 2 471000000 Hz 7.5 dBmV 42.9 dB 78155798 7051 24460
4 Locked QAM256 3 477000000 Hz 8.0 dBmV 42.9 dB 78159856 6867 24205
5 Locked QAM256 4 483000000 Hz 8.2 dBmV 42.9 dB 78162762 6986 24985
6 Locked QAM256 5 489000000 Hz 8.5 dBmV 43.0 dB 78166755 7098 24668
7 Locked QAM256 6 495000000 Hz 8.5 dBmV 43.1 dB 78169632 6926 25728
8 Locked QAM256 7 501000000 Hz 8.8 dBmV 43.2 dB 78172644 7236 25290
9 Locked QAM256 8 507000000 Hz 8.9 dBmV 43.0 dB 78168585 7857 27712
10 Locked QAM256 9 513000000 Hz 9.8 dBmV 43.0 dB 78170063 8696 29010
11 Locked QAM256 10 519000000 Hz 9.3 dBmV 42.9 dB 78180866 7546 26616
12 Locked QAM256 11 525000000 Hz 8.9 dBmV 42.8 dB 78183282 7272 27044
13 Locked QAM256 12 531000000 Hz 8.6 dBmV 42.6 dB 78189304 7139 25917
14 Locked QAM256 13 537000000 Hz 8.4 dBmV 42.5 dB 78193580 7370 26377
15 Locked QAM256 14 543000000 Hz 8.5 dBmV 42.6 dB 78197056 7090 25912
16 Locked QAM256 15 549000000 Hz 8.3 dBmV 42.5 dB 78201098 7623 27026
17 Locked QAM256 16 555000000 Hz 8.2 dBmV 42.3 dB 78204373 7247 25882
18 Locked QAM256 17 561000000 Hz 8.3 dBmV 42.3 dB 78208777 7643 26960
19 Locked QAM256 18 567000000 Hz 8.3 dBmV 42.2 dB 78211708 7615 26575
20 Locked QAM256 19 573000000 Hz 8.4 dBmV 42.1 dB 78214785 7414 25697
21 Locked QAM256 20 579000000 Hz 8.6 dBmV 42.0 dB 78220178 7692 26818
22 Locked QAM256 21 585000000 Hz 8.4 dBmV 42.0 dB 78223346 7689 26461
23 Locked QAM256 22 591000000 Hz 8.4 dBmV 41.7 dB 78226762 7753 26295
24 Locked QAM256 23 597000000 Hz 8.2 dBmV 41.8 dB 78231583 7305 25563
25 Locked QAM256 24 603000000 Hz 8.2 dBmV 41.9 dB 78234545 7192 25846
26 Locked QAM256 25 609000000 Hz 8.3 dBmV 41.9 dB 78238808 7374 26207
27 Locked QAM256 26 615000000 Hz 8.4 dBmV 41.1 dB 78242439 7702 27054
28 Locked QAM256 27 621000000 Hz 8.5 dBmV 41.8 dB 78245521 7013 23028
29 Locked QAM256 28 627000000 Hz 8.3 dBmV 41.7 dB 78250432 7510 25628
30 Locked QAM256 30 639000000 Hz 8.2 dBmV 41.3 dB 78254451 7585 26376
31 Locked QAM256 31 645000000 Hz 8.6 dBmV 41.5 dB 78256189 7215 25728
32 Locked QAM256 32 651000000 Hz 8.6 dBmV 41.4 dB 78252292 6452 22796

<tabindex=-1>Upstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 36800000 Hz 40.0 dBmV
2 Locked ATDMA 2 30400000 Hz 40.0 dBmV
3 Locked ATDMA 3 24000000 Hz 40.0 dBmV
4 Not Locked Unknown 0 0 Hz 0.0 dBmV
5 Not Locked Unknown 0 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Hz 0.0 dBmV

<tabindex=-1>Downstream OFDM Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier Number Range Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked 0, 1, 255 159 702000000 Hz 10.7 dBmV 40.5 dB 1126 ~ 2969 220808091 154349259 2
2 Not Locked 0, 255 0 0 Hz 7.5 dBmV 0.0 dB 0 ~ 4095 0 0 0

<tabindex=-1>Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked Unknown 0 0 Hz 0 dBmV
2 Not Locked Unknown 0 0 Hz 0 dBmV

Current System Time: Sat Dec 22 20:31:45 2018 

 

 
 
 
 
Time Priority Description
2018-12-22, 20:22:38 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;
2018-12-22, 20:03:05 Warning (5) REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;
2018-12-22, 20:02:59 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 .;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:6c:bc:b9:1e:ad;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:6c:bc:b9:1e:ad;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=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2018-12-22, 19:44:19 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:6c:bc:b9:1e:ad;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=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;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=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;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=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;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=78:d2:94:fd:bd:90;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) Telnet user logged out.
Frequent Visitor

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Just another update. I haven't had a single issue with my connection going down since exchanging my Aris SB8200 for a Netgear CM1000. I haven't even had the slow downs or pauses where the modem is visibly up by its indication lights but you can't get a webpage to pull up. I'm starting to think either the SB8200 is no longer compatible with Comcast in my area or that firmware update that was pushed caused all the issues.
Official Employee

Re: SB8200 is it the modem or is it Comcast/Xfinity: SERIOUS Connection Issues

Thanks for reporting back, kickguru. Glad to see you were able to mitigate the issue by replacing that modem. I cannot assume what the root cause of the issue was, but it feels as though there was a hardware of firmware issue with that modem you exchanged. 

 

Please let me know if you need any other assistance. 


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