Spectator

Frequent Disconnects, T3+T4 Timeouts

I've been having frequent disconnects over the past week or so.  Had a tech come out yesterday evening (4/19) and he said he couldn't find any issues and that the signal levels were good.  The modem is a TP-Link TC-7610. I checked and all the connections were tight.

 

Had a similar issue a few months back with constant T3/T4 timeouts.  The tech removed a bad splitter and added an impeder (i think) and it resolved the issue until now.  I've made no changes since then. Any input is appreciated!

 

ProcedureStatus Comment
Acquire Downstream Channel531000000 HzLocked
Connectivity StateOKOperational
Boot StateOKOperational
Configuration FileOK?BiABGZgIwAEAAAAAAAAAAHKY3tD6aUomBGAADAkAVX18kdb4MqHI@AAAAAFbw5+9ub9b_LO_PdZBF15sQg31_
SecurityEnabledBPI+

 
Downstream Bonded Channels

Channel Status Modulation Channel ID Frequency Power SNR
1LockedQAM2561531000000 Hz2.5 dBmV40.4 dB
2LockedQAM2562537000000 Hz2.8 dBmV40.8 dB
3LockedQAM2563543000000 Hz2.3 dBmV40.7 dB
4LockedQAM2564549000000 Hz2.7 dBmV40.8 dB
5LockedQAM2565555000000 Hz2.8 dBmV40.3 dB
6LockedQAM2566561000000 Hz3.1 dBmV40.8 dB
7LockedQAM2567567000000 Hz3.1 dBmV40.9 dB
8LockedQAM2569579000000 Hz2.8 dBmV40.7 dB
Upstream Bonded Channels

Channel Status Channel Type Channel ID Symbol Rate Frequency Power
1LockedATDMA185120 ksym/sec24200000 Hz51.0 dBmV
2LockedTDMA172560 ksym/sec19400000 Hz52.2 dBmV
3LockedATDMA195120 ksym/sec30600000 Hz51.0 dBmV
4LockedATDMA205120 ksym/sec37000000 Hz51.0 dBmV

 

Fri Apr 20 02:42:10 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Thu Apr 19 00:26:37 2018Error (4)Missing BP Configuration Setting TLV Type: 17.9;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;CM-QOS=1.1;CM-VER=3.0;
Thu Apr 19 00:26:37 2018Error (4)Missing BP Configuration Setting TLV Type: 17.8;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;CM-QOS=1.1;CM-VER=3.0;
Time Not EstablishedNotice (6)Overriding MDD IP initialization parameters; IP provisioning mode = IPv6
Time Not EstablishedCritical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 19:01:17 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:54:23 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:54:07 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:49:06 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:48:42 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:46:57 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:46:32 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:46:31 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:46:00 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:43:35 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:43:17 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:40:18 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:40:02 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:37:46 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:37:20 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:31:40 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:31:22 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:31:15 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:30:50 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:29:12 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:28:40 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:27:09 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:27:02 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:24:38 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:24:20 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
Wed Apr 18 17:21:20 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=98:de:d0:fa:69:4a;CMTS-MAC=00:01:5c:8b:d4:60;...
Wed Apr 18 17:21:05 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=98...
9 REPLIES
Helper

Re: Frequent Disconnects, T3+T4 Timeouts

Upstream levels are on the very high side.  T3 time-outs are almost always caused by upstream issues. The levels are not fine. If all connections are tight and coax everywhere from the modem to the main incoming line is good it could be a coax issue on the street or farther back. 

 

It could also be that you have too many splitters or really long coax runs. Can you describe you connection from the main to the modem? Splitters, length of coax runs, etc.?

Spectator

Re: Frequent Disconnects, T3+T4 Timeouts

We switched to antennae so the only connection in between the modern and the hookup is the impeder and ground installed by the first tech, no split to a cable box. I uploaded a picture of the connection here https://i.imgur.com/y3gImx7?r.  The coax is about 20-30 feet from where it comes in the wall to the modern. Thanks.

Helper

Re: Frequent Disconnects, T3+T4 Timeouts

The coupler is inserting loss to the signal, perhaps to decrease the download power levels, but that also impacts the upload levels. Your modem is now screaming to be heard .  If you bypass the Commscope coupler and connect the line to the modem directly to the ground block you should be good. It will bring down the upload power levels. Can you try this and repost your signal levels? 

Highlighted
Spectator

Re: Frequent Disconnects, T3+T4 Timeouts

Alrighty, detached the coupler.

 

Procedure Status Comment
Acquire Downstream Channel567000000 HzLocked
Connectivity StateOKOperational
Boot StateOKOperational
Configuration FileOK?BiABGZgIwAEAAAAAAAAAAHKY3tD6aUomBGAADAkAVX18kdb4MqHI@AAAAAEKeQ+K5WUZtjWinFat5z5gG5t9_
SecurityEnabledBPI+

 
Downstream Bonded Channels

Channel Status Modulation Channel ID Frequency Power SNR
1LockedQAM2567567000000 Hz12.3 dBmV40.8 dB
2LockedQAM2568573000000 Hz12.4 dBmV40.8 dB
3LockedQAM25611591000000 Hz11.3 dBmV39.9 dB
4LockedQAM25612597000000 Hz11.1 dBmV39.9 dB
5LockedQAM25613603000000 Hz11.3 dBmV39.9 dB
6LockedQAM25614609000000 Hz10.8 dBmV39.8 dB
7LockedQAM25615615000000 Hz10.4 dBmV39.1 dB
8LockedQAM25616621000000 Hz10.2 dBmV39.4 dB
Upstream Bonded Channels

Channel Status Channel Type Channel ID Symbol Rate Frequency Power
1LockedATDMA185120 ksym/sec24200000 Hz35.5 dBmV
2LockedTDMA172560 ksym/sec19400000 Hz36.0 dBmV
3LockedATDMA195120 ksym/sec30600000 Hz36.5 dBmV
4LockedATDMA205120 ksym/sec37000000 Hz36.5 dBmV
Helper

Re: Frequent Disconnects, T3+T4 Timeouts

I think this will take care of your T3 timeouts. Keep an eye on the event log to see if something else starts happening, perhaps a different issue that the coupler was there to fix. 

Spectator

Re: Frequent Disconnects, T3+T4 Timeouts

Awesome, thanks for the help. I will continue to monitor it for while.

Spectrum Employee

Re: Frequent Disconnects, T3+T4 Timeouts

Much better with a lower Tx/Transmit/Return/Upstream  power level!

 

And @reds91185 was completely correct that the 52.2 dBmV on 19.4MHz earlier was causing T3 & T4 timeouts.  It's logged on server side.  Was causing packet loss even on the upstream.

 

Too high Tx and/or too low Rx/ will definitely cause issues with internet (and even cable TV too if it gets bad enough).

 

Additionally, having a bunch of extra wires attached to a splitter not being used could add to ingress noise if any of those wires has bad quality or loosely connected fittings/connectors. And open ports even could potentially add to microreflections and ingress if not terminated.  Combine low Rx and/or high Tx with noise from ingress, and internet issues are assured to happen (and intermittently at that).

 

@wwkane33 

Rule of thumb, if more than 2 or 3 outlets, typically want to use a unity-gain amp instead of a splitter. 

Just one example of such a house/drop amp: http://www.antronix.com/files//DS-1106-AR_VRA900B.pdf

(not to be confused with a street amp or LE)

Spoiler
We don't stock 4-way splitters in our weekly tackleboxes we get from the warehouse anymore for this reason, they are orderable sure but not in the regular supply for the reason that it causes Tx to be too high. (we're in an encrypted QAM market, where every outlet needs a box, and typically a box that needs true-2-way communication, upstead & downstream both).
My postings on this site are my own, off-the-clock, and don’t necessarily represent TWC’s/Charter's strategies or opinions.
Spectator

Re: Frequent Disconnects, T3+T4 Timeouts

@agentx5 Always good to have confirmation, thanks. I wish I had saved the connection info and event logs from when the problem originally cropped up. I'm curious what the first tech saw that prompted him to install the coupler after getting rid of the bad splitter we had put in and why that resolved the issues temporarily. 

Contributor

Re: Frequent Disconnects, T3+T4 Timeouts

Whatever tech put in that 'fix' needs to have a bit of re-education.  He is using a coupler to get 9 dB of attenuation, but then leaves the through port unterminated.  That's a no-no.  And that coupler seems to have a very skewed frequency response.  Removing it you picked up 9 dB on the down stream but a whopping +15 dB on the upstream. 

 

If you still experience problems, forget the tech and just install a simple 6 dB inline attenuator where that couple was.   https://www.amazon.com/6db-Attenuator-Pad-1-each/dp/B0013L48XA