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I've started experiencing intermittment connectivity loss with my Arris SB6183 in early April. I tried reseting, reverting changes on my router (pfSense 2.4), reseting the route, rolling back router updates etc...
So, I ordered a Arris SB8200 thinking hey I've had this modem for awhile so I'll give it a shot and upgrade. Same issue. Tried different router hardware, same issue. Tried an old netgear, same issue.
Contacted Comcast and got the run around that it was my equipment even though the 6183 worked for years prior. After some hemming and hawing, I got a tech out here. He noticed a splitter in the basement with around 8 connections (we only have the TV and modem). He removed the extra connections keeping just the 2. He also replaced the line from the pole to the house as he said it was probably 15+ years old given the sheathing on it.
The irony is the day he came, I hadn't experience the drop at all that day but normally it happened 2-5 times a day. Usually rebooting the modem only worked. Sometimes a release\renew on the router was necessary.
When this happened, I wasn't able to hit the modem status page until lastnight which is when I saw DOCIS Network Access Enabled: Denied and Connectivty State: Access Denied. Screenshot attached.
Sometimes it would stay steady for a couple of hours. Other times it would last 15-30 minutes before needing another kick.
Channel levels below. I also see this in the log alot. It doesn't actually have any new log entries either. It's either from earlier this month or from 1/1/1970
Any help or pointers before I call support again would be greatly appreciated!
"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 16:13:58 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx;CMTS-MAC=xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 16:7:58 Critical(3) "Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=xx:xx:xx;CMTS-MAC=xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;"
|Downstream Bonded Channels|
|Channel ID||Lock Status||Modulation||Frequency||Power||SNR/MER||Corrected||Uncorrectables|
|29||Locked||QAM256||675000000 Hz||2.0 dBmV||40.6 dB||0||0|
|1||Locked||QAM256||507000000 Hz||3.0 dBmV||41.7 dB||0||0|
|2||Locked||QAM256||513000000 Hz||3.1 dBmV||41.6 dB||1||0|
|3||Locked||QAM256||519000000 Hz||3.0 dBmV||41.4 dB||0||0|
|4||Locked||QAM256||525000000 Hz||2.9 dBmV||41.3 dB||0||0|
|5||Locked||QAM256||531000000 Hz||3.0 dBmV||41.2 dB||0||0|
|6||Locked||QAM256||537000000 Hz||3.0 dBmV||41.3 dB||0||0|
|7||Locked||QAM256||543000000 Hz||3.3 dBmV||41.2 dB||0||0|
|8||Locked||QAM256||549000000 Hz||3.6 dBmV||41.2 dB||0||0|
|9||Locked||QAM256||555000000 Hz||4.2 dBmV||41.6 dB||0||0|
|10||Locked||QAM256||561000000 Hz||4.6 dBmV||41.8 dB||0||0|
|11||Locked||QAM256||567000000 Hz||4.7 dBmV||41.7 dB||0||0|
|12||Locked||QAM256||573000000 Hz||4.8 dBmV||41.6 dB||0||0|
|13||Locked||QAM256||579000000 Hz||4.9 dBmV||41.4 dB||0||0|
|14||Locked||QAM256||585000000 Hz||4.7 dBmV||41.3 dB||1||0|
|15||Locked||QAM256||591000000 Hz||4.4 dBmV||41.3 dB||0||0|
|16||Locked||QAM256||597000000 Hz||4.1 dBmV||41.2 dB||0||0|
|17||Locked||QAM256||603000000 Hz||4.1 dBmV||41.2 dB||0||0|
|18||Locked||QAM256||609000000 Hz||3.7 dBmV||41.2 dB||0||0|
|19||Locked||QAM256||615000000 Hz||3.4 dBmV||41.1 dB||0||0|
|20||Locked||QAM256||621000000 Hz||3.2 dBmV||41.0 dB||0||0|
|21||Locked||QAM256||627000000 Hz||2.7 dBmV||40.7 dB||0||0|
|22||Locked||QAM256||633000000 Hz||2.5 dBmV||40.7 dB||0||0|
|23||Locked||QAM256||639000000 Hz||2.1 dBmV||40.7 dB||0||0|
|24||Locked||QAM256||645000000 Hz||2.0 dBmV||40.6 dB||0||0|
|25||Locked||QAM256||651000000 Hz||2.1 dBmV||40.9 dB||0||0|
|26||Locked||QAM256||657000000 Hz||1.9 dBmV||40.7 dB||0||0|
|27||Locked||QAM256||663000000 Hz||1.9 dBmV||40.7 dB||0||0|
|28||Locked||QAM256||669000000 Hz||2.1 dBmV||40.8 dB||0||0|
|30||Locked||QAM256||681000000 Hz||2.1 dBmV||40.5 dB||0||0|
|31||Locked||QAM256||687000000 Hz||2.4 dBmV||40.6 dB||0||0|
|32||Locked||QAM256||693000000 Hz||2.5 dBmV||40.6 dB||0||0|
|159||Locked||Other||702000000 Hz||4.7 dBmV||39.8 dB||924||3|
|Upstream Bonded Channels|
|Channel||Channel ID||Lock Status||US Channel Type||Frequency||Width||Power|
|1||1||Locked||SC-QAM||36500000 Hz||6400000 Hz||44.5 dBmV|
|2||2||Locked||SC-QAM||30100000 Hz||6400000 Hz||45.0 dBmV|
|3||3||Locked||SC-QAM||23700000 Hz||6400000 Hz||44.5 dBmV|
Your power levels look pretty good, but you clearly have something going on there. Since you've already had a tech out...
I've asked an employee to check the CMTS for real-time and historical RF signal reports from your modem. They can also check your local node/plant for any degradation or error reports. You can expect a reply in this thread.
FYI: They owe you a $20 credit for every tech visit after the first for the same problem. You can also get a credit for your service from the time you first reported the issue until it is resolved.
Hello shaun040. I can assist with further troubleshooting your intermittent connectivity issues. As nerdburg suggested, 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 and account primary phone number so I can access your equipment.