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Forum Discussion
Slow Upload Speeds on CM1000
I'm experiencing slow upload speeds with my CM1000 cable modem on Comcast's network. My plan is for 300Mbps down, 25Mbps upstream. The download speed is close to 300, but the upload speed ranges fr...
I've used various sites including speedtest.xfinity.com. On Comcast's site I get 8 Mbps up. For most other sites, I get a lower value, including for testmy.net I get 1-2 Mbps up.
Here are some diagnostics:
Startup Procedure Procedure Status Comment Acquire Downstream Channel 501000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enable BPI+ IP Provisioning Mode Honor MDD IPv6 only Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 1 501000000 Hz -4.3 dBmV 34.8 dB 1757896329 2 0 2 Locked QAM256 2 507000000 Hz -4.1 dBmV 35.2 dB 1757981574 7 0 3 Locked QAM256 3 513000000 Hz -4.4 dBmV 36.8 dB 1757991529 2 0 4 Locked QAM256 4 519000000 Hz -4.1 dBmV 37.9 dB 1758000571 3 0 5 Locked QAM256 5 525000000 Hz -4.3 dBmV 38.2 dB 1757996771 2 0 6 Locked QAM256 6 531000000 Hz -4.2 dBmV 38.2 dB 1758019361 1 0 7 Locked QAM256 7 537000000 Hz -3.8 dBmV 35.9 dB 1758028180 7 0 8 Locked QAM256 8 543000000 Hz -4.1 dBmV 37.6 dB 1758037685 1 0 9 Locked QAM256 9 555000000 Hz -4.1 dBmV 36.6 dB 1758053097 0 0 10 Locked QAM256 10 561000000 Hz -4.6 dBmV 38.0 dB 1758062473 0 0 11 Locked QAM256 11 567000000 Hz -4.1 dBmV 38.2 dB 1758072040 1 0 12 Locked QAM256 12 573000000 Hz -4.2 dBmV 38.2 dB 1758080995 1 0 13 Locked QAM256 13 579000000 Hz -4.7 dBmV 38.1 dB 1758090912 1 0 14 Locked QAM256 14 585000000 Hz -4.6 dBmV 38.0 dB 1758099878 1 0 15 Locked QAM256 15 591000000 Hz -5.1 dBmV 38.0 dB 1758109215 5 0 16 Locked QAM256 16 597000000 Hz -4.7 dBmV 38.0 dB 1758118694 1 0 17 Locked QAM256 17 603000000 Hz -4.5 dBmV 38.0 dB 1758144398 7 0 18 Locked QAM256 18 609000000 Hz -4.7 dBmV 38.0 dB 1758153128 2 0 19 Locked QAM256 19 615000000 Hz -4.4 dBmV 38.0 dB 1758134012 0 0 20 Locked QAM256 20 621000000 Hz -4.4 dBmV 29.9 dB 1758064993 106959 21 21 Locked QAM256 21 627000000 Hz -5.0 dBmV 33.3 dB 1758180416 28 0 22 Locked QAM256 22 633000000 Hz -4.6 dBmV 37.9 dB 1758185578 0 0 23 Locked QAM256 23 639000000 Hz -5.0 dBmV 37.9 dB 1758199258 7 0 24 Locked QAM256 24 645000000 Hz -5.1 dBmV 37.1 dB 1758208851 5 0 25 Locked QAM256 26 651000000 Hz -5.1 dBmV 36.1 dB 1758234773 0 0 26 Locked QAM256 27 657000000 Hz -5.9 dBmV 36.8 dB 1758242943 3 0 27 Locked QAM256 28 663000000 Hz -5.0 dBmV 37.8 dB 1758249000 6 0 28 Locked QAM256 29 669000000 Hz -5.2 dBmV 38.0 dB 1758255529 8 0 29 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0 30 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0 31 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0 32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0 Upstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 73 35600000 Hz 46.8 dBmV 2 Locked ATDMA 74 29200000 Hz 47.3 dBmV 3 Locked ATDMA 75 22800000 Hz 47.3 dBmV 4 Locked ATDMA 76 16000000 Hz 46.8 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 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 25 720000000 Hz -5.6 dBmV 27.5 dB 1108 ~ 2987 81678594 25215901 0 2 Not Locked 0 0 0 Hz -5.1 dBmV 0.0 dB 0 ~ 4095 0 0 0 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
Here is my event log, taken from 10/2 at 10:40 AM EST -- I've masked the MAC addresses:
Time Priority Description 2017-10-01, 22:50:10 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:xx:xx:xx:xx;CMTS-MAC=00:01:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1; 2017-10-01, 22:50:07 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 .;CM-MAC=a0:04:xx:xx:xx:xx;CMTS-MAC=00:01:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1; Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6 Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=a0:04:xx:xx:xx:xx;CMTS-MAC=00:01:xx:xx:xx:xx;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=a0:04:xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2017-10-01, 22:34:44 Critical (3) Resetting the cable modem due to docsDevResetNow Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=a0:04:xx:xx:xx:xx;CMTS-MAC=00:01:xx:xx:xx:xx;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=a0:04:xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; 2017-10-01, 22:31:01 Critical (3) Resetting the cable modem due to docsDevResetNow 2017-10-01, 22:26:02 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:xx:xx:xx:xx;CMTS-MAC=00:01:xx:xx:xx:xx;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=a0:04:xx:xx:xx:xx;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=a0:04:xx:xx:xx:xx;CMTS-MAC=00:01:xx:xx:xx:xx;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=a0:04:xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
power levels look good.
have you had better US speeds before?
Please PM me you CM MAC, CMTS MAC, and location of the device (city, state).
I believe so. The reason this came to my attention is that I'm sharing videos via Plex with a friend. Before this worked without issue, but now we are getting major buffering issues. I think 8 Mbps up would not cause buffering issues for the size/quality of the videos I am sharing, but it appears my real upload speed is closer to 2 Mbps according to testmy.net (and others) -- this speed could be the source of our buffering issues, and at any rate I would expect to get upload speeds much closer to my provisioned speed of 25.
I will PM you those details.
Hello, I have this same Modem with Xfinity and got that same event log about the DS profile change. I have also been gettng T3 timeouts with slow loading pages and had to quit using IE11 completely because of speed issues. Some of my regular speed test slow down at the end of the download test and then timeout on the upload side. I was wonering if this had been solved for you yet? For me this all started around a week ago. Xfinity even replaced my outside cabling but the issue still persist.
I am still debugging it and believe the issue may be related to a Comcast network issue in my area -- waiting to check again once that is resolved. As for the entries in the event log -- I'm not sure, Netgear support never mentioned anything about them to me, and I think they may be just related to times when I rebooted the cable modem. I don't believe they are related to the slow upload speed issue. Good luck.