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Visitor
kcahill
Posts: 4
Registered: ‎01-03-2011

T4 time out

I am getting constant t4 time out issues that cause packet loss anywhere between 10-25% I have tried everything including replacing cables, router, cable modem etc and have not been able to fix this. Sometimes it goes well for a day or two but then it starts all over.

 

Sample Modem Logs:

 

 

6 01/03/11 13:59:13 R07.0 critical Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

7 01/03/11 13:59:35 T05.0 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

8 01/03/11 13:59:40 T202.0 warning Lost MDD Timeout;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

9 01/03/11 14:02:33 D01.0 critical DHCP FAILED - Discover sent, no offer received;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

10 01/03/11 14:06:52 T05.0 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

11 01/03/11 14:06:57 T202.0 warning Lost MDD Timeout;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

12 01/03/11 14:31:22 T05.0 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

13 01/03/11 14:31:27 T202.0 warning Lost MDD Timeout;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

14 01/03/11 14:31:44 R04.0 critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

15 01/01/00 00:00:17 T05.0 critical SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

16 01/01/00 00:00:21 T202.0 warning Lost MDD Timeout;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

 

17 01/03/11 15:13:30 E113.0 notice Ethernet Link-up

 

I have searched online and seen everything from this is an ISP issue to a Line issue to etc, but does anyone have any experience with this problem in the Renton or Seattle area?

Cable Expert
JayInAlg
Posts: 12,046
Registered: ‎03-02-2007

Re: T4 time out

[ Edited ]

T4's are RF issues with the downstream signals, and need a tech out to find and repair the issue.  It could be local to your home with the issue between the tap along the drop cable, & coax cables to the modem, or many times up into the Comcast plant to the node.

 

Your log doesn't show alot of T4's, so please share your modem stats with your browser http://192/168.100.1

 

Nothiing you could do other than changing coax in the house would fix it, and most likey it is outside.

  

The Comcast Corp administrator has been notified of your T4's and will get  the  right people on it.

 

If you already have had contact with Comcast support about this, please share your call and tech visit history.

 

Watch this post and your email for updates from the team in the next couple of days.

Visitor
kcahill
Posts: 4
Registered: ‎01-03-2011

Re: T4 time out

CM Configuration file name d11_m_5341_silver_c01.cm Network Access Permitted

 

Downstream Frequency to tune to: 591000000    Hz

Scanning start frequency: 999000000 Hz

Channel Frequency: 590997925 Hz 596999146 Hz 603000488 Hz 609001709 Hz

Modulation: 256 QAM 256 QAM 256 QAM 256 QAM

Signal strength: 1.3831 dBmV 2.4909 dBmV 2.0242 dBmV 0.7936 dBmV

Signal noise ratio: 35.247 dB 35.247 dB 35.247 dB 35.247 dB

 

Upstream Channel Id: 1


Upstream Frequency: 30600000 Hz


Upstream bandwidth: 6400000 Hz


Transmission signal strength: 46.5000 dBmV

 

 

I have called and gotten the restart the modem, take everything out of the loop except the modem etc, standard troubleshooting by step. I have not had a service call.

 

This problem really got bad after the windstorm 2 weeks ago so I am doubting it is on my side. I can post expanded logs with T4 timeouts if you want.

Cable Expert
JayInAlg
Posts: 12,046
Registered: ‎03-02-2007

Re: T4 time out

The Comcast Corp admin has been notified and will decide on the next step to take.  He will follow up so no need to call or post anywhere else.

Retired Administrator
CC_Dete
Posts: 2,486
Registered: ‎07-01-2010

Re: T4 time out

These aren't T4 timeouts; rather lost syncs between your modem and the CMTS. Are you able to post ping tests to demonstrate the packet loss. I did check into this and your signals look great.

Just 'Dete'
Retired Help Forums Admin
Visitor
kcahill
Posts: 4
Registered: ‎01-03-2011

Re: T4 time out

Yeah next time it happens I will post some ping tests, they are normally either 4-10% or 25% and usually happen at around 8-9pm or early morning.

Retired Administrator
CC_Dete
Posts: 2,486
Registered: ‎07-01-2010

Re: T4 time out

 


kcahill wrote:

Yeah next time it happens I will post some ping tests, they are normally either 4-10% or 25% and usually happen at around 8-9pm or early morning.


Thanks

 

Just 'Dete'
Retired Help Forums Admin
Visitor
kcahill
Posts: 4
Registered: ‎01-03-2011

Re: T4 time out

[ Edited ]
IndexDate/TimeIDLevelText
101/07/11 11:32:00T05.0criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;
201/07/11 11:32:02T202.0warningLost MDD Timeout;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;
301/07/11 11:32:04T05.0criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;
401/07/11 11:38:15R07.0criticalUnicast Ranging Received Abort Response - initializing MAC;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;
501/07/11 11:39:15R02.0criticalNo Ranging Response received - T3 time-out;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;
601/07/11 11:39:19R09.0warningB-INIT-RNG Failure - Retries exceeded;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;
701/07/11 11:39:45R02.0critical

No Ranging Response received - T3 time-out;CM-MAC=00:05:ca:a5:76:44;CMTS-MAC=00:1d:70:cc:4f:b8;CM-QOS=1.1;CM-VER=3.0;

I wasnt online when this happened so I couldnt run the ping test but I found it in my log when I got home today.