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Intermittent connectivity due to Ranging response T4 timeouts

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Intermittent connectivity due to Ranging response T4 timeouts

It's been 6 weeks with countless calls, 3 technician visits, 3 modems and nothing has changed. The issue documented in this article under T3 and T4 Timeouts is EXACTLY what I am experiencing: https://forums.xfinity.com/t5/Internet/ANSWERED-Tips-for-troubleshooting-your-Xfinity-Internet/ta-p/...

Thank you to whoever put the time in to create this article. 

It has been my experience that Support has no clue about this article.  They should definitely be educated on it.  They should also be educated that Field Technicians can only address issues from the pedastal to the home (in my case) and inside the home.  Intermittent T4 timeouts are beyond their authority/job requirement/expertise.  They need to stop defaulting to a field tech as it is very costly for Comcast to roll a truck especially when it doesn't accomplish anything.

 

I've had a very experienced field tech (15 years with Comcast) who thought the issue was related to high noise levels in the line between the pedestal and the home.  He showed me the levels and we thought this would resolve it.  So he installed a new drop, removed splitters, added new connections in the home. I've also replaced the modem twice to rule out any equipment issues.  Still having issues.

 

I've showed the Modem Event Logs to every Field Tech who has visited.  They don't like to look at it and prefer their own.  But, they can definitely see the modem disconnects which correclate exactly to my T4 timouts..  The last tech said he couldn't do anything about this intermittent unless he was connected to the tap while the T4 ranging issue was occuring.  I told him to hang out for a while and wait because it was going to happen sooner or later.  Of course, that didnt' happen. 

The next thing he said was that he would need get his supervisor to talk to a Line Maintenance supervisor (bucket truck) in order to get someone to inspect the the line from the pedastal to the node in the neighborhood.  He said the likelihood of that happening was slim to none.  He only offered potential causes such as something wrong at the node or someone "backing into my services" which I still don't quite understand.

 

Things brings me to my desperate plea for help on this forum.  I work from home for a cloud computing company and this is un-freaking-bareable.  Below is a log of events from this morning (I have a catalog of these from the past few weeks).  Notice the number of T4 timeouts.  Also notice that my equipment power levels are within spec.

Does anyone have any ieas what to do next since sending a Field Tech (internal supports default answer for everything) seemingly has not the answer?  

 

Please help!

 

Time Priority Description
     
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
     
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:01 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:15 Critical (3) Ranging Request Retries exhausted
May 25 2018 09:58:15 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 09:58:20 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:02:25 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 10:03:02 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 10:07:51 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:12:09 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 10:12:39 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:12:56 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 10:21:55 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:22:39 Critical (3) Ranging Request Retries exhausted
May 25 2018 10:22:39 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 10:22:54 Critical (3) Ranging Request Retries exhausted
May 25 2018 10:22:54 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 10:22:59 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:27:03 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 10:27:32 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:27:52 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 10:32:54 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:33:37 Critical (3) Ranging Request Retries exhausted
May 25 2018 10:33:37 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted
May 25 2018 10:33:58 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:38:01 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 10:38:33 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:38:53 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 10:42:21 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:46:40 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 10:47:17 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 10:52:04 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 10:56:22 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 10:57:03 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 11:03:09 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 11:07:28 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 11:08:01 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 11:08:14 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
May 25 2018 11:11:43 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 11:16:01 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
May 25 2018 11:16:25 Critical (3) No Ranging Response received - T3 time-out
May 25 2018 11:16:43 Warning (5) MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
 
 
Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 657000000 Hz Locked
Connectivity State Ok Operational
Boot State Ok Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables UnCorrectables
1 Locked QAM 256 1 465000000 Hz 4.1 dBmV 38.6 dB 0 0
2 Locked QAM 256 2 471000000 Hz 3.9 dBmV 38.9 dB 0 0
3 Locked QAM 256 3 477000000 Hz 4.1 dBmV 38.9 dB 0 0
4 Locked QAM 256 4 483000000 Hz 4.8 dBmV 38.9 dB 0 0
5 Locked QAM 256 5 489000000 Hz 5.4 dBmV 38.6 dB 0 0
6 Locked QAM 256 6 495000000 Hz 5.9 dBmV 40.3 dB 0 0
7 Locked QAM 256 7 501000000 Hz 5.8 dBmV 38.9 dB 0 0
8 Locked QAM 256 8 507000000 Hz 6.1 dBmV 38.9 dB 2 0
9 Locked QAM 256 9 513000000 Hz 6.5 dBmV 38.9 dB 0 0
10 Locked QAM 256 10 519000000 Hz 6.5 dBmV 38.6 dB 0 0
11 Locked QAM 256 11 525000000 Hz 6.8 dBmV 38.9 dB 0 0
12 Locked QAM 256 12 531000000 Hz 7.1 dBmV 38.9 dB 0 0
13 Locked QAM 256 13 537000000 Hz 7.0 dBmV 38.6 dB 6 0
14 Locked QAM 256 14 543000000 Hz 7.0 dBmV 38.9 dB 0 0
15 Locked QAM 256 15 555000000 Hz 7.1 dBmV 38.9 dB 8 0
16 Locked QAM 256 16 561000000 Hz 7.0 dBmV 38.9 dB 0 0
17 Locked QAM 256 17 567000000 Hz 7.5 dBmV 38.6 dB 0 0
18 Locked QAM 256 18 573000000 Hz 7.4 dBmV 38.9 dB 0 0
19 Locked QAM 256 19 579000000 Hz 7.4 dBmV 38.9 dB 0 0
20 Locked QAM 256 20 585000000 Hz 7.8 dBmV 38.6 dB 0 0
21 Locked QAM 256 21 591000000 Hz 7.5 dBmV 38.9 dB 0 0
22 Locked QAM 256 22 597000000 Hz 7.5 dBmV 38.9 dB 0 0
23 Locked QAM 256 23 603000000 Hz 7.8 dBmV 38.9 dB 0 0
24 Locked QAM 256 24 609000000 Hz 7.6 dBmV 39.2 dB 0 0
25 Locked QAM 256 25 615000000 Hz 7.5 dBmV 38.6 dB 0 0
26 Locked QAM 256 26 621000000 Hz 7.3 dBmV 37.9 dB 0 0
27 Locked QAM 256 27 627000000 Hz 7.4 dBmV 37.9 dB 0 0
28 Locked QAM 256 28 633000000 Hz 7.0 dBmV 38.9 dB 0 0
29 Locked QAM 256 29 639000000 Hz 7.4 dBmV 36.9 dB 0 0
30 Locked QAM 256 30 645000000 Hz 7.4 dBmV 38.9 dB 0 0
31 Locked QAM 256 32 651000000 Hz 7.1 dBmV 37.9 dB 0 0
32 Locked QAM 256 33 657000000 Hz 7.5 dBmV 38.6 dB 19 31

Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 39.5 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 40.0 dBmV
3 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 39.8 dBmV
4 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV
5 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV
6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV
7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV

 

 @ComcastJessie @nerdburg

 

Expert

Re: Intermittent connectivity due to Ranging response T4 timeouts

Since you already had tech visits, I'm going to try escalating your ongoing issue to the Comcast corporate employees that are available to these boards. You should get a reply here in your topic.



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

Re: Intermittent connectivity due to Ranging response T4 timeouts

Lbrau40, thanks for posting. If you've had that many techs with T4 timeouts, there should be a reference to a line tech in one of those jobs. Let's take a closer look. I got your private message that you sent to Jessie, so I'll reach out to you there. 

 

KenF


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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.
Was your question answered? Mark the post as Best Answer!
Regular Visitor

Re: Intermittent connectivity due to Ranging response T4 timeouts

I just wanted to provide a follow up to this issue in case anyone is exeriencing this...

I'm happy to report that I am no longer seeing ANY RANGING issues.  It is so nice not being knocked offline throughout the day due to intermittent T4 Timeouts.  It is also great to look at the Event Logs in the modem and see nothing! Absolutely no events T3, T4, MIMO, etc. 

 

The issue was resolved when Comcast sent a VIP technician to my home along with a line maintenance person (bucket truck).  I never spoke to the line maintenance person, but according to the work order, he replaced a port and faceplate on the pedastal ("tap") for my home.

 

To his credit, the VIP tech knew a ton and also did extensive research prior to arrival and during the visit.  Of course he rechecked all of the other tech's work (4 previous techs) and found some minor issues which he corrected.  He also checked to see if my neighbor who share the pedastal was experiencing the same intermittent problems.  We ruled out an issue with the headend (CMTS) or the line to the headend since my neighbor, who shares a pedastal with me, was not experiencing the issue. 

We didn't rule out internal wiring within the home (the line from the box on the outside of the home to the modem outlet) because that would have required a contractor to come in and do the work.  So when he left the home I still had doubts BUT I didn't see ranging issues throughout the day. 

Finally, the next day I was curious because I hadn't seen any issues so I had to ask what they did and ComcastZach (from this forum) mentioned the following:   "The maintenance team checked the ports on the tap and ended up replacing one along with replacing a face plate." 

 

Thank you ComcastZach and ComcastKen for helping along the way.  This issue was going on for 6 weeks and I hope someone can benefit from this experience and this information.  While it is not easy (nearly impossible) to get a maintenance person to visit your location, perhaps you can refer to this post if you are experiencing the same.

 

Field technicians have limitations on what they can check.  If there has been a disruption in the line back to the beyond my pedastal, they can not do anything about it.   They can check everything (connetions, wires, etc.) from the pedastal (ground) or pole to the box on your home.  And then, the connections inside the home to the modem.  Other than adding compression fittings to the end of the wire, they can't/won't mess with the wiring that your home was built with (from box to your outlet). Sometimes there is a switch or splitter in your attic/garage that they will inspect.

 

Posting below some information:

Modem involved during this: Xfinity Gateway, Netgear CM700 (2 of them as I thought the modem was the problem)

Router: Nighthawk AC2300 with Dynamic QoS (I thought that was causing the issue, but no)

 

Good luck!