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Very Unstable Internet Speeds

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Frequent Visitor

Very Unstable Internet Speeds

Modem is a Netgear CM500-100NAS and my plan is the 100Mbps. Was using a years old Motorola gateway rental and everything was fine. With new equipment, constant lag spikes/latency/packetloss not sure what you would call it. Comcast speedtests return averages around 85Mbps to lows of 5Mbps. Not tech savy, but looking at the logs and things appear in bad shape . This is without the router hooked up. Can anyone give any insight or recommendations what to do? Is the modem junk?

 

Signal Levels:
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
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 7 519000000 Hz 0.9 dBmV 39.3 dB 775 375
2 Locked QAM256 8 525000000 Hz 0.6 dBmV 39.3 dB 20 22
3 Locked QAM256 9 531000000 Hz 0.2 dBmV 39.6 dB 26 19
4 Locked QAM256 10 537000000 Hz 1 dBmV 39.7 dB 24 17
5 Locked QAM256 11 543000000 Hz 1.1 dBmV 39.4 dB 27 17
6 Locked QAM256 12 549000000 Hz 1 dBmV 39.5 dB 24 17
7 Locked QAM256 13 555000000 Hz 1.3 dBmV 39.1 dB 19 20
8 Locked QAM256 14 561000000 Hz 1.2 dBmV 39.7 dB 22 19
9 Locked QAM256 15 567000000 Hz 0.9 dBmV 39.9 dB 20 22
10 Locked QAM256 16 573000000 Hz 1.4 dBmV 40 dB 21 17
11 Locked QAM256 17 579000000 Hz 1.7 dBmV 39.8 dB 28 12
12 Locked QAM256 18 585000000 Hz 1.3 dBmV 39.7 dB 21 20
13 Locked QAM256 19 591000000 Hz 1.5 dBmV 39.7 dB 22 22
14 Locked QAM256 20 597000000 Hz 1.6 dBmV 39.9 dB 13 26
15 Locked QAM256 21 603000000 Hz 0.8 dBmV 39.8 dB 17 20
16 Locked QAM256 22 609000000 Hz 0.3 dBmV 39.8 dB 21 16

Upstream Bonded Channels (Partial Service)
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 35800000 Hz 47 dBmV
2 Not Locked Unknown 2 0 Ksym/sec 29400000 Hz 0.0 dBmV
3 Not Locked Unknown 3 0 Ksym/sec 23000000 Hz 0.0 dBmV
4 Not Locked Unknown 4 0 Ksym/sec 16600000 Hz 0.0 dBmV

Extended Upstream Transmit Power
Enable Extended Upstream Transmit Power

 

And the modem errors:

 

Time Priority Description
2020-1-24, 11:23:45 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:44 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:23 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:22 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:23:01 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:59 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:38 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:37 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:16 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:15 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:15 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;
2020-1-24, 11:22:15 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:bf:5c:70;CMTS-MAC=00:01:5c:73:a0:4b;CM-QOS=1.1;CM-VER=3.0;

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Diamond Problem Solver

Re: Very Unstable Internet Speeds

Per what you posted, your missing 2, possibly 3 upstream channels (depending on the market). You only show 1.

I am a Retired Official Comcast Employee
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Frequent Visitor

Re: Very Unstable Internet Speeds -SOLVED

SOLVED

I knew it had to be either the line or the modem and thankfully it was something as simple as a loose connection behind the plate going into the wall. Modem is working great at the new 200Mbps speed and very stable.