Modem CM500: many channels not locked; slow connection (1-2mbps)

[tcq]

See below. Is it normal for many channels not locked? The Internet starts fast, but over one hour or so drops to crawl speed (1mpbs or less). A reboot of the modem often fixes the problem, but it will gets slow again over time. Is this a cable problem or modem problem? Any advice is appreciated!

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 519000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels (Partial Service)

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 2 519000000 Hz 0.2 dBmV 40.3 dB 0 0 2 Locked QAM256 3 525000000 Hz -0.4 dBmV 34.7 dB 0 0 3 Locked QAM256 4 531000000 Hz -0.7 dBmV 38.2 dB 0 0 4 Locked QAM256 5 537000000 Hz -1.6 dBmV 39.5 dB 0 0 5 Locked QAM256 6 543000000 Hz -2 dBmV 39.6 dB 0 0 6 Not Locked Unknown 7 549000000 Hz 0.0 dBmV 0.0 dB 0 0 7 Not Locked Unknown 8 555000000 Hz 0.0 dBmV 0.0 dB 0 0 8 Not Locked Unknown 9 561000000 Hz 0.0 dBmV 0.0 dB 0 0 9 Not Locked Unknown 10 567000000 Hz 0.0 dBmV 0.0 dB 0 0 10 Not Locked Unknown 11 573000000 Hz 0.0 dBmV 0.0 dB 0 0 11 Locked QAM256 12 579000000 Hz -10.5 dBmV 32.8 dB 94 0 12 Not Locked Unknown 27 687000000 Hz 0.0 dBmV 0.0 dB 0 0 13 Not Locked Unknown 29 699000000 Hz 0.0 dBmV 0.0 dB 0 0 14 Locked QAM256 30 705000000 Hz 1 dBmV 39.9 dB 0 0 15 Locked QAM256 31 717000000 Hz 1.7 dBmV 39.8 dB 0 0 16 Locked QAM256 32 723000000 Hz 1.4 dBmV 39.5 dB 0 0

Upstream Bonded Channels (Partial Service)

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 73 5120 Ksym/sec 17300000 Hz 46.8 dBmV 2 Locked ATDMA 74 5120 Ksym/sec 23700000 Hz 46.8 dBmV 3 Locked ATDMA 75 5120 Ksym/sec 30300000 Hz 50.3 dBmV 4 Not Locked Unknown 76 0 Ksym/sec 36700000 Hz 0.0 dBmV

[vkdelta · Accepted solution]

you have a serious noise issue either in home wiring or ISP's line. that is why most your downstream channels are NOT locked. and whatever is locked have lot of uncorrectable errors. 

what modem did you have before CM500? did it have same problem? or you are moving into a new house/apartment?

[vkdelta]

please post the screenshots of connection page, event logs and who is your ISP? 

did you try with device directly connected to the modem?

have you tried isolating your Router?

[tcq]

ISP: comcast/xfinity.

[tcq]

Event Log

Clear Log                Refresh

Time Priority Description 2017-10-11, 21:49:07 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:49:28 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:49:28 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:49:29 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:49:50 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:49:50 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:49:52 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:13 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:13 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:14 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:35 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:35 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:37 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:57 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:57 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:50:59 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:51:19 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:51:19 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:51:21 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:51:42 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:51:42 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:51:44 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:04 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:04 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:05 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:27 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:27 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:28 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:49 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:49 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:52:50 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:11 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:11 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:12 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:33 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:33 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:34 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:55 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:55 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0; 2017-10-11, 21:53:57 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=10:da:43:fc:c9:48;CMTS-MAC=00:01:5c:63:e0:7b;CM-QOS=1.1;CM-VER=3.0;

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[tcq]

Cable Connection

Apply               Cancel      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 Startup Procedure Procedure Status Comment Acquire Downstream Channel 519000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4) Downstream Bonded Channels (Partial Service) Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 2 519000000 Hz 0.2 dBmV 40.3 dB 0 0 2 Locked QAM256 4 531000000 Hz -0.8 dBmV 39.9 dB 1 0 3 Locked QAM256 6 543000000 Hz -2.2 dBmV 39.6 dB 1 0 4 Not Locked Unknown 7 549000000 Hz 0.0 dBmV 0.0 dB 0 0 5 Not Locked Unknown 9 561000000 Hz 0.0 dBmV 0.0 dB 0 0 6 Locked QAM256 12 579000000 Hz -10.6 dBmV 33.9 dB 39 0 7 Not Locked Unknown 13 585000000 Hz 0.0 dBmV 0.0 dB 0 0 8 Not Locked Unknown 14 591000000 Hz 0.0 dBmV 0.0 dB 0 0 9 Not Locked Unknown 17 609000000 Hz 0.0 dBmV 0.0 dB 0 0 10 Not Locked Unknown 21 633000000 Hz 0.0 dBmV 0.0 dB 0 0 11 Not Locked Unknown 22 639000000 Hz 0.0 dBmV 0.0 dB 0 0 12 Not Locked Unknown 23 645000000 Hz 0.0 dBmV 0.0 dB 0 0 13 Locked QAM256 24 651000000 Hz -3.5 dBmV 29.9 dB 3410759 19271 14 Locked QAM256 30 705000000 Hz 1 dBmV 39.9 dB 2 0 15 Locked QAM256 31 717000000 Hz 1.7 dBmV 39.9 dB 1 0 16 Locked QAM256 32 723000000 Hz 1.2 dBmV 39.7 dB 1 0 Upstream Bonded Channels (Partial Service) Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 73 5120 Ksym/sec 17300000 Hz 47.8 dBmV 2 Locked ATDMA 74 5120 Ksym/sec 23700000 Hz 47.8 dBmV 3 Locked ATDMA 75 5120 Ksym/sec 30300000 Hz 51 dBmV 4 Not Locked Unknown 76 0 Ksym/sec 36700000 Hz 0.0 dBmV Current System Time:Wed Oct 11 21:55:14 2017

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[vkdelta]

please dont copy paste. instead attach them as screenshots. 

from the info you have provided (I could not see Uncorrectables in the power page), it looks like you have US noise issue on comcast and thats why you are seeing lot of T3 timeouts in the event log. But this will cause low performance in US and not in downlink. 

please post screenshot of the power page and not copy-paste them in the reponse as it misses right most columns.

[tcq]

Thank you for the help and sorry for the inconvience of copy&paste.

[vkdelta · Accepted solution]

you have a serious noise issue either in home wiring or ISP's line. that is why most your downstream channels are NOT locked. and whatever is locked have lot of uncorrectable errors. 

what modem did you have before CM500? did it have same problem? or you are moving into a new house/apartment?

[tcq]

Following your advice, we got technical to check cable outside the house. The problem was there indeed. This case is solved. Thank you!

[vkdelta]

great. thanks for update.