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New 1 Gigibit Service: not getting full speeds

New Poster

New 1 Gigibit Service: not getting full speeds

Hello,

I was wondering someone could look at my logs and see if anything obvious. I am getting around 620 Mbps to max of 700 Mbps.  Upload speeds are at 40 Mbps so those are okay.  I just upgraded and in the 30 day plan window so want to see if can improve before that is up since otherwise will downgrade back to 400 Mbps service.

 

I did review the troubleshooting guide and tried as many things to simplify including:

  1. direct connection bypassing router (Asus 68P)
  2. using xfinity speed test site
  3. cable modem is ARRIS SB8200
  4. I have an Intel X550 10Gbps Ethernet card and 10Gps switch so no bottle necks there.
  5. Disconnected tv and multi splitter in interior distribution box so that the main cable into house connects directly to cable modem (one coupler).  Outside looks like no splitters from where comes up from ground and into house.

Thanks for any guidance/help on resolving. 

 

I am getting these errors in the event log:

2-20-2019, 17:29:10 Warning(5) "Dynamic Range Window violation"
2-20-2019, 17:28:33 Critical(3) "Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=3c:04:61:fe:a0:65;CMTS-MAC=58:97:bd:98:69:d1;CM-QOS=1.1;CM-VER=3.1;"

 

Here is my status info:

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 657000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK  
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed  

 

Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 4 Locked SC-QAM 16500000 Hz 6400000 Hz 39.5 dBmV
2 1 Locked SC-QAM 36100000 Hz 6400000 Hz 41.5 dBmV
3 2 Locked SC-QAM 29600000 Hz 6400000 Hz 41.0 dBmV
4 3 Locked SC-QAM 23000000 Hz 6400000 Hz 40.0 dBmV

 

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
29 Locked QAM256 657000000 Hz -5.4 dBmV 38.0 dB 0 0
1 Locked QAM256 489000000 Hz -3.1 dBmV 39.3 dB 0 0
2 Locked QAM256 495000000 Hz -3.3 dBmV 39.1 dB 0 0
3 Locked QAM256 501000000 Hz -3.6 dBmV 39.1 dB 0 0
4 Locked QAM256 507000000 Hz -3.4 dBmV 39.1 dB 0 0
5 Locked QAM256 513000000 Hz -3.1 dBmV 39.2 dB 0 0
6 Locked QAM256 519000000 Hz -3.1 dBmV 39.2 dB 0 0
7 Locked QAM256 525000000 Hz -3.3 dBmV 38.9 dB 0 0
8 Locked QAM256 531000000 Hz -3.2 dBmV 38.9 dB 0 0
9 Locked QAM256 537000000 Hz -3.3 dBmV 38.8 dB 0 0
10 Locked QAM256 543000000 Hz -3.5 dBmV 38.5 dB 0 0
11 Locked QAM256 549000000 Hz -3.5 dBmV 38.5 dB 0 0
12 Locked QAM256 555000000 Hz -3.3 dBmV 38.7 dB 0 0
13 Locked QAM256 561000000 Hz -3.0 dBmV 38.6 dB 0 0
14 Locked QAM256 567000000 Hz -2.8 dBmV 38.8 dB 0 0
15 Locked QAM256 573000000 Hz -2.4 dBmV 38.8 dB 0 0
16 Locked QAM256 579000000 Hz -2.0 dBmV 39.0 dB 0 0
17 Locked QAM256 585000000 Hz -2.0 dBmV 39.0 dB 0 0
18 Locked QAM256 591000000 Hz -2.1 dBmV 39.1 dB 0 0
19 Locked QAM256 597000000 Hz -2.1 dBmV 39.1 dB 0 0
20 Locked QAM256 603000000 Hz -2.5 dBmV 39.1 dB 0 0
21 Locked QAM256 609000000 Hz -2.8 dBmV 38.9 dB 0 0
22 Locked QAM256 615000000 Hz -3.1 dBmV 38.7 dB 0 0
23 Locked QAM256 621000000 Hz -3.1 dBmV 38.7 dB 0 0
24 Locked QAM256 627000000 Hz -3.5 dBmV 38.6 dB 0 0
25 Locked QAM256 633000000 Hz -3.6 dBmV 38.7 dB 0 0
26 Locked QAM256 639000000 Hz -4.1 dBmV 38.6 dB 0 0
27 Locked QAM256 645000000 Hz -4.6 dBmV 38.3 dB 0 0
28 Locked QAM256 651000000 Hz -5.1 dBmV 38.0 dB 0 0
30 Locked QAM256 663000000 Hz -5.7 dBmV 37.9 dB 0 0
31 Locked QAM256 669000000 Hz -5.6 dBmV 37.8 dB 0 0
159 Locked Other 690000000 Hz -0.8 dBmV 36.2 dB 0 0
Highlighted
Expert

Re: New 1 Gigibit Service: not getting full speeds

Hi @sundogak 

Thank you for visiting the forums! 

I've asked an employee to assist you. You should expect a reply in this thread. 


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!
Official Employee

Re: New 1 Gigibit Service: not getting full speeds

Hi, sundogak. Welcome to the community, thanks for reaching out. I will be happy to help you out with your questions/concerns relating to your internet service and speed. I do want to make sure that you also reference this link: https://www.xfinity.com/support/articles/requirements-to-run-xfinity-internet-service to ensure your system meets the necessary requirements. There are a lot of potential contributing factors. When you hardwired directly to the modem after bypassing the router, what were your speeds? Your modem logs and signal levels look OK, there doesn't seem to be a signal issue present or anything like that. T3 timeouts are pretty common, as long as they're not occurring frequently. Let me know once you check that link and please provide your speed results after the hardwired connection, direct to modem. Thank you.!


I am an Official Comcast Employee.
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.
Was your question answered? Mark the post as Best Answer!
New Poster

Re: New 1 Gigibit Service: not getting full speeds

Hi, thanks for confirming the event logs looked good.  I met the minimum standards and this computer is actually on a 10 gigabit setup internal to house network.  I had also done a direct connect with my laptop and was getting the 620 megabit value I noted earlier (which was also what I was getting from PC via my switch). 

 

But with the info that the incoming signal you checked looked good, I took some time to double check things this evening.  As usual, it boils down to something simple.....a cable. Apparently one of my newer Cat 7 10gigabit patch cables that I used to direct connect to the cable modem is faulty (looks like connector was loose).  When I replaced it with one of my older Cat 6 patch cables my test speeds went back up to the max (~940 MBit).  So much for the expensive cables. 

 

Anyway, all is good and I am getting the upper limit consistently at this point so problem solved and issue can be closed.

 

Thanks for the assist.   

Official Employee

Re: New 1 Gigibit Service: not getting full speeds

You are most welcome! I really appreciate the update, thank you very much for elaborating on it too. I will go ahead and complete this request/interaction, I'm glad to hear that everything is back on track with your internet service and speed. Thank you for your time and for being a customer of ours. Take care!


I am an Official Comcast Employee.
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.
Was your question answered? Mark the post as Best Answer!