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Re: Extremely Slow Upload Speeds

New Poster

Re: Extremely Slow Upload Speeds

Recently started experiencing the same thing.

Some background: Up until about a year and a half ago we had regular Comcast Internet and TV service with minimal issues. Then we upgraded to the X1 service and bundled phone with it. We immediately started having issues with our internet service as the router would reset due to high noise on the line. We had two lines coming into our house, one for data and one for TV. The TV line seemed fine but the data line was the one with the bad SNR. After having a couple of over-the-phone sessions with techs they said the problem was either at the connection at the pole or at our house. After 6 techs came out to look at the problem we got two possible issues. The first two techs claimed that it was a "well-known issue in the line and that a tech with a cherry picker would need to come out and fix it at the pole. I called Comcast and requested a tech with a crane to look at the connection and the next two techs that came out only had ladders and, due to some neighbor's trees could not check the connection at the pole. The first of the two techs confirmed that the connection coming from the pole was poor due to high noise. The second one didn't even check, he just said he couldnt't get up to the pole due to not having a crane. The last two techs claimed that the there was no SNR issue and that the issue was with the internal wiring in our house. Since the TV line was solid they suggested moving the modem to that line (sharing the line with our X1 TV box). That would have required installing a new phone jack for our phone and security system. So, for the last few months we have been physically moving the modem when we need uninterrupted internet service then moving it back. Today I switched our phone service back to AT&T and permanently moved the modem down to the TV line and now the issue is that our upload speeds rarely go past the 2Mbps mark, much less get to 10Mbps. When we had the modem hooked up to the data line we would have download speeds range from 5Mbps to 40Mbps but rarely higher. Upstream was always a solid 20Mbps regardless of what was happening with the downstream. I have reset the modem to the factory settings, set Bridge mode since we use a wireless router and disabled the modem's WiFi but still no luck. Any ideas?

Regular Contributor

Re: Extremely Slow Upload Speeds

Gotta fix the line issue unless it happens to be a bad splitter in the house somewhere.  Sounds like the tech narrowed it down to the line or the TAP at the pole.

New Poster

Re: Extremely Slow Upload Speeds

The problem seemed to resolve itself a day later and it seems it may have been the new modem "settling in". Was getting 150+ Mbps down and ~20Mbps up. However, in the last couple of days I've been getting good download speeds but upload is barely pushing 1 Mbps. I have reset the modem twice and reset our Airport Extreme twice to see if that helps. No luck. I checked out the modem logs and noticing a "Started Unicast Maintenance Rating - No Response received - T3 time-out" message. 

 

Time Priority Description
2018-1-31, 00:59:03 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:92:2e:7b;CM-QOS=1.1;CM-VER=3.0;
2018-2-1, 01:11:29 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:92:2e:7b;CM-QOS=1.1;CM-VER=3.0;
2018-2-1, 01:14:16 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:92:2e:7b;CM-QOS=1.1;CM-VER=3.0;
2018-2-1, 01:15:00 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-3, 02:12:42 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
1970-1-1, 00:00:21 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:27 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-8, 18:42:47 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
1970-1-1, 00:00:20 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:26 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-8, 18:44:20 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-8, 18:44:51 Critical (3) TFTP failed - Request sent - No Response;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-8, 18:44:51 Critical (3) TFTP Request Retries exceeded, CM unable to register
2018-2-8, 18:45:00 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-8, 18:45:04 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
2018-2-8, 18:45:55 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:09:54 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:09:54 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:10:02 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:10:13 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:10:13 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:11:36 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:33:11 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:33:11 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 19:34:40 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 21:45:37 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 21:45:37 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 21:45:37 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-8, 22:55:37 Critical (3) Resetting the cable modem due to docsDevResetNow
1970-1-1, 00:00:20 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:27 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:22 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:30 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2018-2-10, 20:27:22 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-10, 21:09:11 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-10, 21:09:11 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-10, 21:09:12 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-10, 21:12:37 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-10, 21:12:37 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;
2018-2-10, 21:13:01 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=dc:ef:09:7e:9a:58;CMTS-MAC=00:01:5c:a9:e2:7a;CM-QOS=1.1;CM-VER=3.0;

 

I'm looking at the Modem status and getting this:

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
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 5 519000000 Hz -2.6 dBmV 37.1 dB 391 0
2 Locked QAM256 1 489000000 Hz -2.2 dBmV 37.3 dB 236 0
3 Locked QAM256 2 495000000 Hz -1.9 dBmV 37.3 dB 245 0
4 Locked QAM256 3 507000000 Hz -2.3 dBmV 36.7 dB 313 0
5 Locked QAM256 4 513000000 Hz -2.3 dBmV 37.2 dB 327 0
6 Locked QAM256 6 525000000 Hz -2.8 dBmV 37 dB 442 0
7 Locked QAM256 7 531000000 Hz -3 dBmV 36.9 dB 508 0
8 Locked QAM256 8 537000000 Hz -3.1 dBmV 36.8 dB 592 0
9 Locked QAM256 9 543000000 Hz -3 dBmV 36.8 dB 599 0
10 Locked QAM256 10 549000000 Hz -3 dBmV 36.3 dB 747 0
11 Locked QAM256 11 555000000 Hz -3.5 dBmV 36.5 dB 764 0
12 Locked QAM256 12 561000000 Hz -3.5 dBmV 36.6 dB 822 0
13 Locked QAM256 13 567000000 Hz -3.5 dBmV 36.5 dB 1076 0
14 Locked QAM256 14 573000000 Hz -3.6 dBmV 36.4 dB 1136 0
15 Locked QAM256 15 579000000 Hz -4 dBmV 36.4 dB 1149 0
16 Locked QAM256 18 597000000 Hz -4.1 dBmV 36.4 dB 1305 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 35800000 Hz 48.5 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 29400000 Hz 48.5 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 23000000 Hz 49.3 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 16600000 Hz 49.3 dBmV
 
Current System Time:Sat Feb 10 22:38:48 2018

 

I've attached the Speedtest results for today to show the numbers. Any help would be appreciated. 

Screen Shot 2018-02-10 at 10.30.09 PM.png
Diamond Problem Solver

Re: Extremely Slow Upload Speeds

The upstream power is still too high.

New Poster

Re: Extremely Slow Upload Speeds


@ wrote:

The upstream power is still too high.


What do I need to do to fix that. Is that something on my end or Comcast's?