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Getting slow speeds in past few weeks (Gigabit plan - logs attached)

Hj2206
New Poster

Getting slow speeds in past few weeks (Gigabit plan - logs attached)

Hi All,

 

I am on the gigabit plan and i usually do speed tests twice a week.  In the past few weeks, i've gone from getting 800-900Mbps to ~150Mbps.  I use a Arris Sb8200 modem.  

 

I've done all the troubleshooting steps that I can think of.  I've reset modem (did a hard reset too), used different cables (just in case), hooked directly into the cable line source in garage (with no splitter).  No luck.  I am getting events in my modem log and will paste these below.  Appreciate any help on this.  Thanks.

 

Status:

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
20 Locked QAM256 495000000 Hz -6.6 dBmV 39.9 dB 0 0
12 Locked QAM256 447000000 Hz -6.1 dBmV 40.1 dB 0 0
13 Locked QAM256 453000000 Hz -5.6 dBmV 40.0 dB 0 0
14 Locked QAM256 459000000 Hz -5.8 dBmV 40.3 dB 0 0
15 Locked QAM256 465000000 Hz -5.8 dBmV 40.2 dB 0 0
16 Locked QAM256 471000000 Hz -5.9 dBmV 40.2 dB 0 0
17 Locked QAM256 477000000 Hz -6.2 dBmV 40.0 dB 0 0
18 Locked QAM256 483000000 Hz -6.1 dBmV 40.1 dB 0 0
19 Locked QAM256 489000000 Hz -6.6 dBmV 39.9 dB 0 0
21 Locked QAM256 507000000 Hz -6.0 dBmV 39.4 dB 0 0
22 Locked QAM256 513000000 Hz -5.5 dBmV 40.0 dB 0 0
23 Locked QAM256 519000000 Hz -5.1 dBmV 40.4 dB 0 0
24 Locked QAM256 525000000 Hz -4.7 dBmV 40.5 dB 0 0
25 Locked QAM256 531000000 Hz -4.8 dBmV 40.4 dB 0 0
26 Locked QAM256 537000000 Hz -5.1 dBmV 40.3 dB 0 0
27 Locked QAM256 543000000 Hz -6.3 dBmV 39.8 dB 0 0
28 Locked QAM256 549000000 Hz -6.9 dBmV 39.6 dB 0 0
29 Locked QAM256 555000000 Hz -7.2 dBmV 39.4 dB 0 0
30 Locked QAM256 561000000 Hz -7.1 dBmV 39.5 dB 0 0
31 Locked QAM256 567000000 Hz -6.6 dBmV 39.6 dB 0 0
32 Locked QAM256 573000000 Hz -6.5 dBmV 39.4 dB 0 0
33 Locked QAM256 579000000 Hz -6.1 dBmV 39.7 dB 0 0
34 Locked QAM256 585000000 Hz -6.0 dBmV 39.7 dB 0 0
35 Locked QAM256 591000000 Hz -5.3 dBmV 39.9 dB 0 0
36 Locked QAM256 597000000 Hz -5.4 dBmV 39.9 dB 0 0
37 Locked QAM256 603000000 Hz -5.4 dBmV 39.9 dB 0 0
38 Locked QAM256 609000000 Hz -6.2 dBmV 39.5 dB 0 0
39 Locked QAM256 615000000 Hz -6.3 dBmV 39.4 dB 0 0
40 Locked QAM256 621000000 Hz -7.4 dBmV 39.0 dB 0 0
41 Locked QAM256 627000000 Hz -8.0 dBmV 38.7 dB 0 0
42 Locked QAM256 633000000 Hz -8.1 dBmV 38.8 dB 0 0
48 Locked Other 688000000 Hz -5.3 dBmV 0.0 dB 152076328 2342
Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 4 Locked SC-QAM Upstream 36700000 Hz 6400000 Hz 48.0 dBmV
2 5 Locked SC-QAM Upstream 41200000 Hz 1600000 Hz 49.0 dBmV
3 1 Locked SC-QAM Upstream 17300000 Hz 6400000 Hz 49.0 dBmV
4 2 Locked SC-QAM Upstream 23700000 Hz 6400000 Hz 49.0 dBmV
5 3 Locked SC-QAM Upstream 30300000 Hz 6400000 Hz 48.0 dBmV

 

 

 

Event Log:

06/03/2020 22:10 84020300 5 "MDD message timeout;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:10 74010100 6 "CM-STATUS message sent. Event Type Code: 1; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:10 84020300 5 "MDD message timeout;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:09 74010100 6 "CM-STATUS message sent. Event Type Code: 4; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:09 84020300 5 "MDD message timeout;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:09 74010100 6 "CM-STATUS message sent. Event Type Code: 4; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:09 84020300 5 "MDD message timeout;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:08 74010100 6 "CM-STATUS message sent. Event Type Code: 4; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:08 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:08 84020300 5 "MDD message timeout;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:07 74010100 6 "CM-STATUS message sent. Event Type Code: 4; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"
06/03/2020 22:07 74010100 6 "CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;"

 

 

 

 

EG
Expert

Re: Getting slow speeds in past few weeks (Gigabit plan - logs attached)

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. And the downstream power is on the low / weak side. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.



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Hj2206
New Poster

Re: Getting slow speeds in past few weeks (Gigabit plan - logs attached)

Thanks.  I likely need a tech to come over.  I did order a new modem but not sure if that will do anything at this point.

EG
Expert

Re: Getting slow speeds in past few weeks (Gigabit plan - logs attached)

A line / connection / signal impairment will still be there no matter what modem is being used. Good luck with it !



I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!