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Much slower speed on the gigabit tier plan

Regular Visitor

Much slower speed on the gigabit tier plan

Hi,

 

I recently upgraded to the gigabit tier plan and purchased the Arris SB8200 as recommended by one of the Xfinity representatives. However, I only get 370Mbps with wired connection and 250Mbps with wireless. Below is my modem status and event log:

 

 
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 675000000 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
28 Locked QAM256 675000000 Hz 6.3 dBmV 41.2 dB 0 0
1 Locked QAM256 513000000 Hz 5.2 dBmV 40.3 dB 0 0
2 Locked QAM256 519000000 Hz 4.9 dBmV 40.1 dB 0 0
3 Locked QAM256 525000000 Hz 5.3 dBmV 40.5 dB 0 0
4 Locked QAM256 531000000 Hz 5.8 dBmV 40.8 dB 0 0
5 Locked QAM256 537000000 Hz 5.8 dBmV 40.7 dB 0 0
6 Locked QAM256 543000000 Hz 5.7 dBmV 40.6 dB 0 0
7 Locked QAM256 549000000 Hz 6.0 dBmV 40.6 dB 0 0
8 Locked QAM256 555000000 Hz 6.5 dBmV 40.9 dB 0 0
9 Locked QAM256 561000000 Hz 6.5 dBmV 40.8 dB 0 0
10 Locked QAM256 567000000 Hz 6.4 dBmV 40.9 dB 0 0
11 Locked QAM256 573000000 Hz 6.6 dBmV 41.0 dB 0 0
12 Locked QAM256 579000000 Hz 6.5 dBmV 40.8 dB 0 0
13 Locked QAM256 585000000 Hz 6.3 dBmV 40.5 dB 0 0
14 Locked QAM256 591000000 Hz 6.0 dBmV 40.8 dB 0 0
15 Locked QAM256 597000000 Hz 6.0 dBmV 40.7 dB 0 0
16 Locked QAM256 603000000 Hz 6.8 dBmV 41.1 dB 0 0
17 Locked QAM256 609000000 Hz 6.8 dBmV 41.0 dB 0 0
18 Locked QAM256 615000000 Hz 6.2 dBmV 40.8 dB 0 0
19 Locked QAM256 621000000 Hz 6.1 dBmV 41.0 dB 0 0
20 Locked QAM256 627000000 Hz 6.3 dBmV 41.0 dB 0 0
21 Locked QAM256 633000000 Hz 7.0 dBmV 41.3 dB 0 0
22 Locked QAM256 639000000 Hz 6.8 dBmV 41.2 dB 0 0
23 Locked QAM256 645000000 Hz 6.0 dBmV 41.1 dB 0 0
24 Locked QAM256 651000000 Hz 5.9 dBmV 41.2 dB 0 0
25 Locked QAM256 657000000 Hz 6.3 dBmV 41.3 dB 0 0
26 Locked QAM256 663000000 Hz 6.7 dBmV 41.5 dB 0 0
27 Locked QAM256 669000000 Hz 6.7 dBmV 41.4 dB 0 0
29 Locked Other 732000000 Hz 9.2 dBmV 40.0 dB 0 0

 
Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 5 Locked SC-QAM 36100000 Hz 6400000 Hz 43.5 dBmV
2 6 Locked SC-QAM 29600000 Hz 6400000 Hz 44.0 dBmV
3 7 Locked SC-QAM 23000000 Hz 6400000 Hz 43.8 dBmV
4 8 Locked SC-QAM 16500000 Hz 6400000 Hz 43.5 dBmV

 

Current System Time: Wed May 9 21:51:46 2018

Time Priority Description
5-9-2018, 21:41:5 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:39 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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-9-2018, 21:32:14 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-9-2018, 21:27:5 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-9-2018, 20:18:11 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:38 Critical(3) "No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-9-2018, 7:49:50 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:37 Critical(3) "No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-9-2018, 7:48:33 Critical(3) "Resetting the cable modem due to docsDevResetNow"
5-9-2018, 1:13:0 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-8-2018, 23:22:27 Critical(3) "SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-8-2018, 23:21:19 Critical(3) "Config File Rejected due to Invalid or Unexpected TLV 11 encoding;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-8-2018, 23:21:19 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:56 Critical(3) "No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:45 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:41 Critical(3) "No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-8-2018, 23:19:52 Critical(3) "Resetting the cable modem due to docsDevResetNow"
5-8-2018, 22:40:26 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-8-2018, 22:40:25 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:42 Critical(3) "No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
1-1-1970, 0:0:40 Critical(3) "No Ranging Response received - T3 time-out;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;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=2c:95:69:67:ac:29;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"
5-8-2018, 7:58:27 Critical(3) "Resetting the cable modem due to docsDevResetNow"
5-7-2018, 22:14:38 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:55:5 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:55:5 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:54:39 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:54:39 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:54:12 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:54:11 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:56 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:56 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:49 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:48 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:32 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:32 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:24 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:23 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:2 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:53:1 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:52:46 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:52:46 Critical(3) "SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
5-7-2018, 20:47:24 Critical(3) "SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=2c:95:69:67:ac:29;CMTS-MAC=00:01:5c:9e:7c:46;CM-QOS=1.1;CM-VER=3.1;"
 

 

I have been talking and chatting with several different technicians and we've all been unsuccessful at resolving the issue. I've also read a few different posts here on this forum and see that one of the solutions is to get the Netgear modem instead. Should I replace SB8200 with Netgear one? Thank you for your time and wisdom.

Expert

Re: Much slower speed on the gigabit tier plan

I'd hold off on getting a new modem just yet.

 

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. 

 

 

Official Employee

Re: Much slower speed on the gigabit tier plan

PHTr, thanks for posting. Let's see what's going on at the premise and your area to see if that has anything to do with your slow speeds. Please send me a private message with your full name and phone number tied to your residential services for help.

Regular Visitor

Re: Much slower speed on the gigabit tier plan

@nerdburg Thanks for looking out

@ComcastKenF thanks for handling my case. I have sent you my info!
Official Employee

Re: Much slower speed on the gigabit tier plan

@nerdburg Thanks for looking out

@ComcastKenF thanks for handling my case. I have sent you my info!

Got it!