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Upgraded to 250 mp/s and now internet is slower than before

Regular Visitor

Upgraded to 250 mp/s and now internet is slower than before

Just recently I upgraded my internet speed from 150 mp/s to 250 mp/s and the speed dropped drastically to around 30-60 mp/s where as before the upgrade I was in the 130 mp/s range.  Spoke with customer service who ran through all the normal tests (basically turning on and off the router and resetting the router) and after that didn't work they scheduled a tech to come out.

 

Tech replaced the cables to the house and performed several tests and came up with no answers as to why we were not receiving the speed we were paying for.  Said it could possibly be the cable modem and left.

 

Purchased new modem with the specs he recommended (was using a sb6141 surfboard and upgraded to a Netgear CM1000) and installed that evening.  Nothing changed but the $160 hole in my pocket from the modem purchase.  

 

Called back to customer service trying to get more answers and they again ran through the normal tests and came up with no reasons.  Thinking it was caused by the upgrade I suggested they put me back on my original plan and hoped it would go back to at least the speed I was getting before.  Unfortunately it did not .  

 

Need help in solving this problem.

 

Here are the modem logs

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 2 483000000 Hz -0.1 dBmV 35.9 dB 47939564 0 0
2 Locked QAM256 3 489000000 Hz -0.1 dBmV 35.8 dB 46759665 0 0
3 Locked QAM256 4 495000000 Hz -0.1 dBmV 36.0 dB 46763071 0 0
4 Locked QAM256 5 507000000 Hz 1.7 dBmV 36.3 dB 46767321 2 0
5 Locked QAM256 6 513000000 Hz 1.3 dBmV 36.5 dB 46770582 0 0
6 Locked QAM256 7 519000000 Hz 1.1 dBmV 36.4 dB 46774635 0 0
7 Locked QAM256 8 525000000 Hz 1.5 dBmV 36.6 dB 46777960 0 0
8 Locked QAM256 9 531000000 Hz 0.9 dBmV 36.4 dB 46776402 0 0
9 Locked QAM256 10 537000000 Hz 0.9 dBmV 36.5 dB 46779916 0 0
10 Locked QAM256 11 543000000 Hz 0.4 dBmV 36.5 dB 46783684 0 0
11 Locked QAM256 12 549000000 Hz 0.1 dBmV 36.5 dB 46787123 0 0
12 Locked QAM256 13 555000000 Hz -0.3 dBmV 36.5 dB 46791324 0 0
13 Locked QAM256 14 561000000 Hz -0.5 dBmV 36.4 dB 46794671 0 0
14 Locked QAM256 15 567000000 Hz -1.2 dBmV 36.3 dB 46798626 0 0
15 Locked QAM256 16 573000000 Hz -2.0 dBmV 36.3 dB 46802132 0 0
16 Locked QAM256 17 579000000 Hz -1.7 dBmV 36.2 dB 46805938 0 0
17 Locked QAM256 18 585000000 Hz -2.9 dBmV 36.1 dB 46809494 0 0
18 Locked QAM256 19 591000000 Hz -3.2 dBmV 35.9 dB 46813809 0 0
19 Locked QAM256 20 597000000 Hz -2.3 dBmV 36.1 dB 46816890 0 0
20 Locked QAM256 21 603000000 Hz -3.7 dBmV 35.7 dB 46821066 0 0
21 Locked QAM256 22 609000000 Hz -3.2 dBmV 35.8 dB 46824385 0 0
22 Locked QAM256 23 615000000 Hz -2.8 dBmV 36.1 dB 46828543 0 0
23 Locked QAM256 24 621000000 Hz -2.9 dBmV 36.1 dB 46832089 0 0
24 Locked QAM256 25 627000000 Hz -2.3 dBmV 36.3 dB 46835801 0 0
25 Locked QAM256 26 633000000 Hz -1.9 dBmV 36.4 dB 46839265 0 0
26 Locked QAM256 27 639000000 Hz -1.6 dBmV 36.4 dB 46843304 0 0
27 Locked QAM256 28 645000000 Hz -1.3 dBmV 36.4 dB 46846937 0 0
28 Locked QAM256 29 651000000 Hz -0.7 dBmV 36.6 dB 46850522 0 0
29 Locked QAM256 30 657000000 Hz -0.5 dBmV 36.7 dB 46854296 0 0
30 Locked QAM256 32 663000000 Hz -1.0 dBmV 36.6 dB 46856712 0 0
31 Locked QAM256 36 669000000 Hz -0.3 dBmV 36.8 dB 46855993 0 0
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 35800000 Hz 38.0 dBmV
2 Locked ATDMA 2 29400000 Hz 38.5 dBmV
3 Locked ATDMA 3 23000000 Hz 37.5 dBmV
4 Locked ATDMA 4 16600000 Hz 37.0 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

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
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 37 722000000 Hz -1.4 dBmV 35.0 dB 1228 ~ 2867 2376431 1974791 0
2 Not Locked 0 0 0 Hz 3.6 dBmV 0.0 dB 0 ~ 4095 0 0 0

 

 

Event logs

2019-09-22, 10:14:21 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1.;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-09-22, 08:35:46 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-09-22, 08:20:27 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-09-21, 06:56:57 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-09-20, 21:48:25 Critical (3) Resetting the cable modem due to docsDevResetNow
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-09-20, 21:09:05 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-09-20, 21:07:38 Critical (3) No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;CM-QOS=1.1;CM-VER=3.1;
2019-09-20, 21:07:28 Critical (3) No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;CM-QOS=1.1;CM-VER=3.1;
2019-09-20, 21:07:08 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:01:5c:ae:00:54;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;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=10:0c:6b:cb:ce:b0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-04-16, 10:48:37 Critical (3) Telnet user logged out.

 

 

Contributor

Re: Upgraded to 250 mp/s and now internet is slower than before

Are you wired into the modem or using wifi? If using wifi are you using the 5g band instead of the 2.4g band? Some setups combind the two bands into one and automatically pick the best one for you, i find i get better proformance  if i can select the one i want manuelly which is the 5g band for me. I have read that comcasts 2.4g band is good for only about 80Mbs where the 5g band can get the 1 gig or close to it.  Those numbers support what i am getting.

Expert

Re: Upgraded to 250 mp/s and now internet is slower than before

Call 1-800-comcast again and ask a rep to completely remove the modem from your account and to "re-provision" it from scratch. Also ask them to confirm that the provisioning and account data in their database is correct and complete and that the correct configuration / bootfile for your subscribed to speed tier is being pushed to the modem.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Regular Visitor

Re: Upgraded to 250 mp/s and now internet is slower than before

Gonna have them re-provision and will post results after
Regular Visitor

Re: Upgraded to 250 mp/s and now internet is slower than before

Asked customer service to re-provision the  modem and they assured me it was tore down and provisioned from scratch.  Still no increase in the speed.  Not sure what to do from here.

Regular Visitor

Slow Internet Speed

I'm currently paying for Blast (150Mbps) and I'm getting speeds of 40/60Mbps down and 11Mbps up while hardwired and close to the same while using the router.   The modem has been re-provisioned from scatch and have had several tech visits which have resulted in a "I have no idea"   Was working correctly until I upgraded to 250mbs and thought that was the problem so I had them bring me back to my original speed tier.  Kind of stuck at the moment and am wondering what my next option could be.

 

My equipment is as follows:

Modem:  Netgear CM1000

Router: Nighthawk R7000

 

Screen Shot 2019-10-01 at 5.12.33 PM.pngdownstreamScreen Shot 2019-10-01 at 5.13.34 PM.pngdownstream/upstreamScreen Shot 2019-10-01 at 5.14.09 PM.pngupstreamScreen Shot 2019-10-01 at 5.14.49 PM.pngError LogsScreen Shot 2019-10-01 at 5.15.03 PM.pngError LogsScreen Shot 2019-10-01 at 5.15.20 PM.pngSpeed Test

 

Any ideas would be helpful.

Expert

Re: Slow Internet Speed

Can't see your pics. Since you are a new poster, they need to be approved by a Forum Admin. That could take some time. In the interim, you could try hosting them at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to them here.



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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!
Official Employee

Re: Slow Internet Speed

Hi @Brittonzink

 

Sorry for the issue you're having with your internet speeds. I'd be happy to help by investigating further. Can you please send a private message including the full name as it appears on the account. To send a Private Message, please click "Comcast_Support” and click “send a message". 


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Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
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