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Visitor

 • 

5 Messages

Fri, Jan 7, 2022 11:09 PM

Closed

Signed up for Ultrafast Internet, but not getting that speed

I signed up for Ultrafast Internet (900 Mbps) toward the end of December, but haven't seen anything above ~160 (about the same as when I had 200 Mbps service). I have a Motorola MB8611 modem and Linksys EA8300 router. The Link Speed under Windows Wi-fi properties varies from 520-650, but speed from the router to WiFi is never more than 160. I have noted some Warnings and Notices in the Event Log of the router, not sure if this is part of the problem. If I can't get Ultrafast speed, I want to cancel to go back to 200 Mbps (before the 30 day no-penalty period expires).

Accepted Solution

Visitor

 • 

5 Messages

12 d ago

I contacted Xfinity support and they verified there was nothing wrong with the connection or the modem. I finally figured out that the problem was with a 'media prioritization' setting on my router. Turning that off (as recommended for download speeds > 200), I now have fast speed from the router (800-900/24). A little embarrassed that I didn't note that earlier!🙄

Official Employee

 • 

207 Messages

@user_6dd336

 

Thank you for updating the post with the solution. As well, thank you for taking the time to reach out to our team so we can investigate your service and connection further. I am so glad we were able to locate the issue causing slower speeds. Please reach back out if you notice any issues in the future. Enjoy your day! 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
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Was your question answered? Please, mark a reply as the Accepted Answer.tick
EG

Expert

 • 

91.7K Messages

@user_6dd336

Ha ! Seen that here before. That QoS stuff will get ya' every time! Glad you got it figured out ! Now closing your marked "Solved" topic. 

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? Please mark an Accepted Answer!tick
EG

Expert

 • 

91.7K Messages

17 d ago

@user_6dd336 

Please redact all of the CM MAC and the CMTS MAC addresses in your error log entries for your privacy.  They are considered to be personal information. Personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".

EG

Expert

 • 

91.7K Messages

17 d ago

@user_6dd336 

Please also post the signal status figures.

Please copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.

Also, what speed do you get with the computer connected directly to the MB8611 cable modem (no router / WiFi in the mix) ?

(edited)

Visitor

 • 

5 Messages

17 d ago

Sorry about the mixup with error log entries - I deleted all of that from the original post.

Here is signal status information. Link speed Receive/Transmit is 1000/1000 Mbps. According to Xfinity speed test, download speed is 358 Mbps, upload is 20.1.

Downstream Bonded Channels

 

  

   Channel

Lock Status

Modulation

Channel ID

Freq. (MHz)

Pwr (dBmV)

SNR (dB)

Corrected

Uncorrected

   1

Locked

QAM256

33

627.0

0.4

42.3

0

0

   2

Locked

QAM256

13

507.0

-0.2

42.7

0

0

   3

Locked

QAM256

14

513.0

-0.4

42.6

0

0

   4

Locked

QAM256

15

519.0

-0.4

42.6

0

0

   5

Locked

QAM256

16

525.0

-0.5

42.6

0

0

   6

Locked

QAM256

17

531.0

-0.5

42.5

0

0

   7

Locked

QAM256

18

537.0

-0.5

42.3

0

0

   8

Locked

QAM256

19

543.0

-0.4

42.6

0

0

   9

Locked

QAM256

20

549.0

-0.3

42.6

0

0

   10

Locked

QAM256

21

555.0

-0.5

42.4

0

0

   11

Locked

QAM256

22

561.0

-0.2

42.5

0

0

   12

Locked

QAM256

23

567.0

-0.4

42.3

0

0

   13

Locked

QAM256

24

573.0

-0.1

42.4

0

0

   14

Locked

QAM256

25

579.0

-0.3

42.3

0

0

   15

Locked

QAM256

26

585.0

-0.2

42.4

0

0

   16

Locked

QAM256

27

591.0

-0.1

42.3

0

0

   17

Locked

QAM256

28

597.0

-0.3

42.3

0

0

   18

Locked

QAM256

29

603.0

0.2

42.3

0

0

   19

Locked

QAM256

30

609.0

-0.4

42.1

0

0

   20

Locked

QAM256

31

615.0

0.3

42.4

0

0

   21

Locked

QAM256

32

621.0

-0.4

42.1

0

0

   22

Locked

QAM256

34

633.0

-0.4

41.9

0

0

   23

Locked

QAM256

35

639.0

0.2

42.1

0

0

   24

Locked

QAM256

36

645.0

-0.3

41.9

0

0

   25

Locked

QAM256

37

651.0

0.1

42.1

0

0

   26

Locked

QAM256

38

657.0

0.0

42.1

0

0

   27

Locked

QAM256

39

663.0

0.0

42.1

0

0

   28

Locked

QAM256

40

669.0

0.4

42.4

0

0

   29

Locked

QAM256

41

675.0

0.0

41.7

0

0

   30

Locked

QAM256

42

681.0

0.6

42.4

0

0

   31

Locked

QAM256

43

687.0

0.0

42.3

0

0

   32

Locked

QAM256

44

693.0

0.6

42.4

0

0

   33

Locked

OFDM PLC

159

722.0

1.3

41.8

1728542

0

   Upstream Bonded Channels

 

  

   Channel

Lock Status

Channel Type

Channel ID

Symb. Rate (Ksym/sec)

Freq. (MHz)

Pwr (dBmV)

   1

Locked

SC-QAM

1

5120

16.4

45.0

   2

Locked

SC-QAM

2

5120

22.8

44.5

   3

Locked

SC-QAM

3

5120

29.2

45.5

   4

Locked

SC-QAM

4

5120

35.6

44.5

   5

Locked

SC-QAM

5

2560

40.4

45.0

EG

Expert

 • 

91.7K Messages

16 d ago

We still needed to see the log entries minus those MAC addys. I asked you to just delete those MAC addy's, not the entire output...

And what about this part: " Also, what speed do you get with the computer connected directly to the MB8611 cable modem (no router / WiFi in the mix) ?"

(edited)

Visitor

 • 

5 Messages

@EG 

The speed with computer directly connected to the cable modem is:

Link speed Receive/Transmit is 1000/1000 Mbps. According to Xfinity speed test, download speed is 862.2 Mbps, upload is 24.2. This is when I am using MS Edge. Oddly, speed is lower running the test from Firefox (460.4/20.1).

Event Log

 

 

 

 Priority

Description

Time Not Established

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;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-QOS=1.1;CM-VER=3.1;

Time Not Established

Critical (3)

No Ranging Response received - T3 time-out;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-QOS=1.1;CM-VER=3.1;

03:43:38

Tue Dec 14 2021

Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

00:09:10

Wed Dec 15 2021

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-QOS=1.1;CM-VER=3.1;

00:09:11

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

00:09:50

Wed Dec 15 2021

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-QOS=1.1;CM-VER=3.1;

00:09:51

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

00:10:30

Wed Dec 15 2021

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-QOS=1.1;CM-VER=3.1;

00:10:39

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

00:11:27

Wed Dec 15 2021

Critical (3)

DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-QOS=1.1;CM-VER=3.1;

00:12:33

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

00:13:24

Wed Dec 15 2021

Critical (3)

DHCP failed - DHCP Solicit sent, No DHCP Advertise received;CM-QOS=1.1;CM-VER=3.1;

00:13:32

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

00:26:28

Wed Dec 15 2021

Critical (3)

SYNC Timing Synchronization failure - Loss of Sync;CM-QOS=1.1;CM-VER=3.1;

01:03:52

Wed Dec 15 2021

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-QOS=1.1;CM-VER=3.1;

01:03:53

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

01:04:02

Wed Dec 15 2021

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-QOS=1.1;CM-VER=3.1;

01:05:27

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

01:07:03

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;CM-QOS=1.1;CM-VER=3.1;

01:07:13

Wed Dec 15 2021

Critical (3)

No Ranging Response received - T3 time-out;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-QOS=1.1;CM-VER=3.1;

Time Not Established

Notice (6)

Honoring MDD; IP provisioning mode = IPv6

13:33:48

Thu Jan 6 2022

Notice (6)

DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-QOS=1.1;CM-VER=3.1;

13:33:54

Thu Jan 6 2022

Warning (5)

REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-QOS=1.1;CM-VER=3.1;

13:33:55

Thu Jan 6 2022

Warning (5)

RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-QOS=1.1;CM-VER=3.1;

13:33:55

Thu Jan 6 2022

Warning (5)

Dynamic Range Window violation

13:33:55

Thu Jan 6 2022

Warning (5)

RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-QOS=1.1;CM-VER=3.1;

13:33:55

Thu Jan 6 2022

Warning (5)

Dynamic Range Window violation

The information below was added as of this morning - actually replaced the entries for 1/6/22 (those disappeared from the log).

17:19:19

Fri Jan 7 2022

Notice (6)

DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-QOS=1.1;CM-VER=3.1;

17:19:24

Fri Jan 7 2022

Warning (5)

REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-QOS=1.1;CM-VER=3.1;

17:19:24

Fri Jan 7 2022

Warning (5)

RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-QOS=1.1;CM-VER=3.1;

17:19:24

Fri Jan 7 2022

Warning (5)

Dynamic Range Window violation

22:32:52

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

22:33:17

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

22:44:16

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

22:44:42

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

22:59:15

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

22:59:43

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

23:09:25

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

23:09:53

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

23:11:20

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

23:11:49

Fri Jan 7 2022

Notice (6)

CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-QOS=1.1;CM-VER=3.1;

 

EG

Expert

 • 

91.7K Messages

16 d ago

Download and try this speed test: https://www.speedtest.net/apps/windows See what you get with it.

It does not run via any browser so it is not affected by any browser impairments / bottlenecks.

So, even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) / an upstream channel-return path impairment somewhere.


There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


In the meantime, I'm going to escalate your issue to the Comcast corporate employees that are available to these boards.  They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !

Visitor

 • 

5 Messages

@EG 

Internet speed with Speedtest app is now 701/24.

Thanks so much for your help!

EG

Expert

 • 

91.7K Messages

@user_6dd336

My pleasure ! 😊 It's why I lurk ! 

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? Please mark an Accepted Answer!tick

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