Re: No Ranging Response received - T3 time-out - Xfinity Help and Support Forums

mctaylr · ‎07-22-2020

I am experiencing the same problem described by the original poster. My modem log shows repeated T3 time-out messages, until eventually the internet connection drops altogether. The problem is intermittent - often 2 to 3 times per day. In between the internet connection is fine, fast and reliable. Then this starts happening and eventually the internet is disconnected entirely.

Here is a recent log:

Jul 22 2020 09:48:51	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 09:49:35	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 09:49:35	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 09:49:59	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 09:56:23	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 09:56:23	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 09:56:47	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:03:11	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:03:11	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:03:35	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:09:59	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:09:59	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:10:23	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:16:47	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:16:47	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:17:11	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:23:35	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:23:35	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:23:59	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:30:23	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:30:23	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:30:47	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:37:11	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:37:11	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:37:35	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:43:59	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:43:59	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:44:23	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:50:48	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:50:48	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:51:11	Critical (3)	No Ranging Response received - T3 time-out
Jul 22 2020 10:57:36	Critical (3)	Ranging Request Retries exhausted
Jul 22 2020 10:57:36	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted
Jul 22 2020 10:58:00	Critical (3)	No Ranging Response received - T3 time-out

I've tried Xfinity support multiple 5 to 6 times over the last 2 weeks. The only solution they offer is rebooting my modem, which is what I have already done - it's the only way to get a connection again.

Please help! My work is suffering as a result of this.

EG · ‎07-22-2020

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

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mctaylr · ‎07-23-2020

Hi @EG .

Here are the Downstream, Upstream and Signal to Noise ratios...

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectable
1	Locked	QAM 256	16	501000000 Hz	1.7 dBmV	40.3 dB	0	0
2	Locked	QAM 256	17	507000000 Hz	2.5 dBmV	40.9 dB	0	0
3	Locked	QAM 256	18	513000000 Hz	2.5 dBmV	40.9 dB	0	0
4	Locked	QAM 256	19	519000000 Hz	1.7 dBmV	40.3 dB	0	0
5	Locked	QAM 256	20	525000000 Hz	2.2 dBmV	40.3 dB	0	0
6	Locked	QAM 256	21	531000000 Hz	2.0 dBmV	40.9 dB	0	0
7	Locked	QAM 256	22	537000000 Hz	2.5 dBmV	40.3 dB	0	0
8	Locked	QAM 256	23	543000000 Hz	2.2 dBmV	38.9 dB	0	0
9	Locked	QAM 256	24	549000000 Hz	2.7 dBmV	40.3 dB	0	0
10	Locked	QAM 256	25	555000000 Hz	2.7 dBmV	40.3 dB	0	0
11	Locked	QAM 256	26	561000000 Hz	2.7 dBmV	40.3 dB	0	0
12	Locked	QAM 256	27	567000000 Hz	3.0 dBmV	40.3 dB	0	0
13	Locked	QAM 256	28	573000000 Hz	2.4 dBmV	40.3 dB	0	1
14	Locked	QAM 256	29	579000000 Hz	2.7 dBmV	40.3 dB	0	0
15	Locked	QAM 256	30	585000000 Hz	2.5 dBmV	38.9 dB	0	1
16	Locked	QAM 256	31	591000000 Hz	3.2 dBmV	40.3 dB	0	0
17	Locked	QAM 256	32	597000000 Hz	3.0 dBmV	40.3 dB	0	1
18	Locked	QAM 256	33	603000000 Hz	3.2 dBmV	40.3 dB	0	0
19	Locked	QAM 256	34	609000000 Hz	2.7 dBmV	38.9 dB	0	0
20	Locked	QAM 256	35	615000000 Hz	2.5 dBmV	38.9 dB	0	0
21	Locked	QAM 256	36	621000000 Hz	3.5 dBmV	40.9 dB	7	0
22	Locked	QAM 256	37	627000000 Hz	3.4 dBmV	40.3 dB	0	0
23	Locked	QAM 256	38	633000000 Hz	3.7 dBmV	40.3 dB	0	1
24	Locked	QAM 256	39	639000000 Hz	3.2 dBmV	38.9 dB	0	0
25	Locked	QAM 256	40	645000000 Hz	3.9 dBmV	39.9 dB	0	0
26	Locked	QAM 256	41	651000000 Hz	3.7 dBmV	39.9 dB	0	0
27	Locked	QAM 256	42	657000000 Hz	3.7 dBmV	39.9 dB	0	0
28	Locked	QAM 256	43	663000000 Hz	4.3 dBmV	39.9 dB	0	0
29	Locked	QAM 256	44	669000000 Hz	4.0 dBmV	39.5 dB	6	0
30	Locked	QAM 256	45	675000000 Hz	5.0 dBmV	39.5 dB	0	0
31	Locked	QAM 256	46	681000000 Hz	4.5 dBmV	39.9 dB	0	0
32	Locked	QAM 256	47	687000000 Hz	4.5 dBmV	39.9 dB	6	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	4	5120 Ksym/sec	17300000 Hz	37.3 dBmV
2	Locked	ATDMA	3	5120 Ksym/sec	23700000 Hz	38.3 dBmV
3	Locked	ATDMA	2	5120 Ksym/sec	30100000 Hz	40.5 dBmV
4	Locked	ATDMA	1	5120 Ksym/sec	36500000 Hz	40.0 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

EG · ‎07-23-2020

The signal stats are o/k but the error log entries indicate that something is going on. Perhaps there is noise ingress into the line(s) 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.

I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS to see whether or not everything is in the green zone, see your node / cable plant and modem health, and also see a history plot for the modem. You should get a reply here in your topic. Good luck !

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ComcastAmir · ‎07-23-2020

Hello mctaylr, (EG) is right checking your signal levels from my end of things will better help us find what's causing your timeouts. To better assist you with this could you please send me a private message with your full name by clicking on my name (ComcastAmir) and then click "Send a message"?

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