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Re: T3 T4 timeout issues with gig / SB8200 dropping internet

New Poster

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

I am having the exact same problem. It has been going on for what seems like the last month or so. Same modem, same errors and the power readings are within optimal range. I’d love to hear if you figure out what is going on.
Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

Start here;


https://forums.xfinity.com/t5/Your-Home-Network/Connection-Troubleshooting-Tips/m-p/1253575#M94474

 

Post the requested info from here;


https://forums.xfinity.com/t5/Your-Home-Network/Information-Requested-for-Connection-Related-Posts/m...

 



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New Poster

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

I have an Arris SB8200.  I currently have a 120mm fan attached to the side to make sure it was cool enough - it seems a bit too hot to the touch several months ago and that seemed to take care of some instability issues I was previously seeing.  I recently just swapped out my router to see if it was the router (previously was an Asus RT-AC66U_B1 but just replaced with my own pfSense firewall) but I am still seeing the same behavior.  My power signals this morning were a bit on the lower side so I pulled the simulator that a tech had previously put on the line where I had too strong of a signal and that put the power levels within -7 and +7 (they were around anywhere from -5 to -11 on the downstream channels).  I don't have any speed issues when it is connected.

 

Here are my upstream and downstream levels:

https://imgur.com/7cSXSly

Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
2	Locked	QAM256	489000000 Hz	0.9 dBmV	43.9 dB	0	0
3	Locked	QAM256	495000000 Hz	1.0 dBmV	44.1 dB	0	0
4	Locked	QAM256	501000000 Hz	0.7 dBmV	43.8 dB	0	0
5	Locked	QAM256	507000000 Hz	0.6 dBmV	43.6 dB	0	0
6	Locked	QAM256	513000000 Hz	0.4 dBmV	43.7 dB	0	0
7	Locked	QAM256	519000000 Hz	0.2 dBmV	43.5 dB	0	0
8	Locked	QAM256	525000000 Hz	0.1 dBmV	43.5 dB	0	0
9	Locked	QAM256	531000000 Hz	-0.3 dBmV	43.2 dB	0	0
10	Locked	QAM256	537000000 Hz	-0.6 dBmV	43.0 dB	0	0
11	Locked	QAM256	543000000 Hz	-0.5 dBmV	43.1 dB	0	0
12	Locked	QAM256	549000000 Hz	-0.7 dBmV	42.9 dB	0	0
13	Locked	QAM256	555000000 Hz	-0.7 dBmV	43.0 dB	0	0
14	Locked	QAM256	561000000 Hz	-0.6 dBmV	43.0 dB	0	0
15	Locked	QAM256	567000000 Hz	-0.5 dBmV	42.8 dB	0	0
16	Locked	QAM256	573000000 Hz	-0.8 dBmV	43.0 dB	0	0
17	Locked	QAM256	579000000 Hz	-1.0 dBmV	42.8 dB	0	0
18	Locked	QAM256	585000000 Hz	-0.8 dBmV	43.0 dB	0	0
19	Locked	QAM256	591000000 Hz	-0.8 dBmV	42.8 dB	0	0
20	Locked	QAM256	597000000 Hz	-0.9 dBmV	42.9 dB	0	0
21	Locked	QAM256	603000000 Hz	-1.0 dBmV	42.8 dB	0	0
22	Locked	QAM256	609000000 Hz	-1.5 dBmV	42.5 dB	0	0
23	Locked	QAM256	615000000 Hz	-1.3 dBmV	42.7 dB	0	0
24	Locked	QAM256	621000000 Hz	-1.2 dBmV	42.7 dB	0	0
25	Locked	QAM256	627000000 Hz	-1.3 dBmV	42.8 dB	0	0
26	Locked	QAM256	633000000 Hz	-1.4 dBmV	42.5 dB	0	0
27	Locked	QAM256	639000000 Hz	-1.8 dBmV	42.5 dB	0	0
28	Locked	QAM256	645000000 Hz	-1.9 dBmV	42.5 dB	0	0
29	Locked	QAM256	651000000 Hz	-2.0 dBmV	42.3 dB	0	0
30	Locked	QAM256	657000000 Hz	-2.0 dBmV	42.3 dB	0	0
31	Locked	QAM256	663000000 Hz	-2.0 dBmV	42.2 dB	0	0
32	Locked	QAM256	669000000 Hz	-2.7 dBmV	41.6 dB	0	0
37	Locked	Other	690000000 Hz	-3.3 dBmV	39.0 dB	40978147	0
Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	1	Locked	SC-QAM Upstream	35800000 Hz	6400000 Hz	48.0 dBmV
2	2	Locked	SC-QAM Upstream	29400000 Hz	6400000 Hz	47.0 dBmV
3	3	Locked	SC-QAM Upstream	23000000 Hz	6400000 Hz	47.0 dBmV
4	4	Locked	SC-QAM Upstream	16600000 Hz	6400000 Hz	47.0 dBmV

 

And here are some recent logs:

https://imgur.com/rRcNKvg

08/03/2019 13:38	82000400	3	"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:38	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:38	82000400	3	"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:37	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:36	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:35	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:35	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 13:34	82000200	3	"No Ranging Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"

 

*edit: sorry, not sure why the images aren't showing up so I had to upload them to imgur.

 

Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

That's o/k right there. See what happens.



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New Poster

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

Well, I am not so sure that my modem is liking the simulator being removed...I'm assuming that this means something about the signal power being too strong so the simulator is actually needed?

 

08/03/2019 14:22	2436694061	5	"Dynamic Range Window violation"
08/03/2019 14:22	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 14:22	2436694061	5	"Dynamic Range Window violation"
08/03/2019 14:22	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 14:22	2436694061	5	"Dynamic Range Window violation"
08/03/2019 14:22	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/03/2019 14:22	2436694061	5	"Dynamic Range Window violation"
08/03/2019 14:22	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

The differences between the signal levels are what needs to be compared, with, and then without the simulator.



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New Poster

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

With the simulator:

Downstream Bonded Channels
Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
2	Locked	QAM256	489000000 Hz	-4.2 dBmV	40.1 dB	177	686
1	Locked	QAM256	483000000 Hz	-4.3 dBmV	40.3 dB	336	1001
3	Locked	QAM256	495000000 Hz	-4.3 dBmV	40.0 dB	295	856
4	Locked	QAM256	501000000 Hz	-4.9 dBmV	39.6 dB	220	843
5	Locked	QAM256	507000000 Hz	-4.7 dBmV	39.8 dB	236	859
6	Locked	QAM256	513000000 Hz	-5.0 dBmV	39.5 dB	259	890
7	Locked	QAM256	519000000 Hz	-5.3 dBmV	39.2 dB	180	772
8	Locked	QAM256	525000000 Hz	-5.6 dBmV	39.1 dB	207	841
9	Locked	QAM256	531000000 Hz	-5.9 dBmV	38.9 dB	246	870
10	Locked	QAM256	537000000 Hz	-5.8 dBmV	39.1 dB	202	917
11	Locked	QAM256	543000000 Hz	-6.5 dBmV	38.3 dB	276	871
12	Locked	QAM256	549000000 Hz	-6.6 dBmV	38.2 dB	901	804
13	Locked	QAM256	555000000 Hz	-6.2 dBmV	38.6 dB	269	828
14	Locked	QAM256	561000000 Hz	-6.3 dBmV	38.4 dB	218	751
15	Locked	QAM256	567000000 Hz	-6.5 dBmV	38.2 dB	190	786
16	Locked	QAM256	573000000 Hz	-7.1 dBmV	37.9 dB	262	746
17	Locked	QAM256	579000000 Hz	-6.8 dBmV	38.1 dB	243	653
18	Locked	QAM256	585000000 Hz	-6.8 dBmV	38.1 dB	212	752
19	Locked	QAM256	591000000 Hz	-7.1 dBmV	37.7 dB	225	754
20	Locked	QAM256	597000000 Hz	-7.2 dBmV	37.7 dB	247	777
21	Locked	QAM256	603000000 Hz	-7.6 dBmV	37.4 dB	224	763
22	Locked	QAM256	609000000 Hz	-7.6 dBmV	37.4 dB	149	672
23	Locked	QAM256	615000000 Hz	-7.8 dBmV	37.3 dB	182	817
24	Locked	QAM256	621000000 Hz	-8.0 dBmV	37.0 dB	236	774
25	Locked	QAM256	627000000 Hz	-7.9 dBmV	37.2 dB	225	684
26	Locked	QAM256	633000000 Hz	-8.2 dBmV	37.1 dB	265	692
27	Locked	QAM256	639000000 Hz	-8.5 dBmV	36.7 dB	178	659
33	Locked	QAM256	459000000 Hz	-4.2 dBmV	40.1 dB	305	1002
34	Locked	QAM256	465000000 Hz	-3.9 dBmV	40.3 dB	298	1075
35	Locked	QAM256	471000000 Hz	-4.1 dBmV	40.1 dB	254	885
36	Locked	QAM256	477000000 Hz	-4.0 dBmV	40.3 dB	273	780
37	Locked	Other	690000000 Hz	-11.0 dBmV	30.5 dB	187897576	0

Upstream Bonded Channels
Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	1	Locked	SC-QAM Upstream	35800000 Hz	6400000 Hz	48.0 dBmV
2	2	Locked	SC-QAM Upstream	29400000 Hz	6400000 Hz	47.0 dBmV
3	3	Locked	SC-QAM Upstream	23000000 Hz	6400000 Hz	47.0 dBmV
4	4	Locked	SC-QAM Upstream	16600000 Hz	6400000 Hz	46.0 dBmV

 

Without the simulator:

Downstream Bonded Channels
Channel ID	Lock Status	Modulation	Frequency	Power	SNR/MER	Corrected	Uncorrectables
2	Locked	QAM256	489000000 Hz	0.9 dBmV	41.9 dB	213	725
1	Locked	QAM256	483000000 Hz	0.7 dBmV	41.7 dB	1024	2339
3	Locked	QAM256	495000000 Hz	0.9 dBmV	41.8 dB	859	2094
4	Locked	QAM256	501000000 Hz	0.6 dBmV	41.6 dB	668	1923
5	Locked	QAM256	507000000 Hz	0.3 dBmV	41.4 dB	777	1850
6	Locked	QAM256	513000000 Hz	0.6 dBmV	41.6 dB	879	2137
7	Locked	QAM256	519000000 Hz	0.3 dBmV	41.3 dB	732	1796
8	Locked	QAM256	525000000 Hz	0.0 dBmV	41.0 dB	776	2008
9	Locked	QAM256	531000000 Hz	-0.2 dBmV	41.1 dB	874	1817
10	Locked	QAM256	537000000 Hz	-0.1 dBmV	40.9 dB	676	2000
11	Locked	QAM256	543000000 Hz	-0.7 dBmV	40.6 dB	840	2198
12	Locked	QAM256	549000000 Hz	-0.6 dBmV	40.7 dB	1405	1851
13	Locked	QAM256	555000000 Hz	-0.3 dBmV	40.8 dB	756	1816
14	Locked	QAM256	561000000 Hz	-0.3 dBmV	40.8 dB	743	1583
15	Locked	QAM256	567000000 Hz	-0.5 dBmV	40.7 dB	642	1768
16	Locked	QAM256	573000000 Hz	-0.5 dBmV	40.6 dB	844	1760
17	Locked	QAM256	579000000 Hz	-0.6 dBmV	40.4 dB	518	1390
18	Locked	QAM256	585000000 Hz	-0.4 dBmV	40.7 dB	667	1598
19	Locked	QAM256	591000000 Hz	-0.6 dBmV	40.5 dB	670	1659
20	Locked	QAM256	597000000 Hz	-0.7 dBmV	40.4 dB	745	1581
21	Locked	QAM256	603000000 Hz	-0.8 dBmV	40.4 dB	726	1574
22	Locked	QAM256	609000000 Hz	-1.2 dBmV	40.1 dB	428	1292
23	Locked	QAM256	615000000 Hz	-1.2 dBmV	40.2 dB	576	1654
24	Locked	QAM256	621000000 Hz	-1.0 dBmV	40.1 dB	615	1555
25	Locked	QAM256	627000000 Hz	-1.1 dBmV	40.2 dB	530	1352
26	Locked	QAM256	633000000 Hz	-1.3 dBmV	40.1 dB	650	1349
27	Locked	QAM256	639000000 Hz	-1.8 dBmV	39.6 dB	465	1299
33	Locked	QAM256	459000000 Hz	0.4 dBmV	41.4 dB	909	2287
34	Locked	QAM256	465000000 Hz	0.8 dBmV	41.8 dB	921	2494
35	Locked	QAM256	471000000 Hz	0.8 dBmV	41.8 dB	829	2023
36	Locked	QAM256	477000000 Hz	0.9 dBmV	41.7 dB	807	1903
37	Locked	Other	690000000 Hz	-3.5 dBmV	35.5 dB	193309217	0


Upstream Bonded Channels
Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	1	Locked	SC-QAM Upstream	35800000 Hz	6400000 Hz	46.0 dBmV
2	2	Locked	SC-QAM Upstream	29400000 Hz	6400000 Hz	45.0 dBmV
3	3	Locked	SC-QAM Upstream	23000000 Hz	6400000 Hz	45.0 dBmV
4	4	Locked	SC-QAM Upstream	16600000 Hz	6400000 Hz	45.0 dBmV
Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

It's better with it out !



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New Poster

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

OK, thanks for the feedback!  I will try it without and see what happens.  Seemed like before it was more unstable without it but I will just leave it be for a bit and see if my connection drops regularly or not.  I really appreciate the quick responses!

Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

Not just better, but they are fully in spec now !



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New Poster

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

Everything was working well last evening until I had another drop of my internet connection this morning.  I checked the cable modem logs:

 

Date Time	Event ID	Event Level	Description
08/04/2019 07:54	82000500	3	"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 07:52	2436694061	5	"Dynamic Range Window violation"
08/04/2019 07:52	82001200	5	"RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 04:44	2436694061	5	"Dynamic Range Window violation"
08/04/2019 04:44	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 04:44	2436694061	5	"Dynamic Range Window violation"
08/04/2019 04:44	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 04:44	2436694061	5	"Dynamic Range Window violation"
08/04/2019 04:44	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 04:44	2436694061	5	"Dynamic Range Window violation"
08/04/2019 04:44	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"
08/04/2019 01:26	2436694061	5	"Dynamic Range Window violation"
08/04/2019 01:26	82001100	5	"RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=18:9c:27:ee:cc:7d;CMTS-MAC=00:01:5c:ad:64:64;CM-QOS=1.1;CM-VER=3.1;"

I was looking at the signal but unfortunately I didn't get a copy of the readings but the one that I noticed was the upstream.  Below is the current output for reference but when I had initially loaded the page before the modem reset, channel 4 power was at like 57 dBmV while the rest were in the mid 40s.  Any idea what would cause a random spike like that?

Upstream Bonded Channels
Channel	Channel ID	Lock Status	US Channel Type	Frequency	Width	Power
1	1	Locked	SC-QAM Upstream	35800000 Hz	6400000 Hz	44.0 dBmV
2	2	Locked	SC-QAM Upstream	29400000 Hz	6400000 Hz	44.0 dBmV
3	3	Locked	SC-QAM Upstream	23000000 Hz	6400000 Hz	44.0 dBmV
4	4	Locked	SC-QAM Upstream	16600000 Hz	6400000 Hz	44.0 dBmV

I'd guess it is these sort of spikes that the cable tech who installed the cable simulator might have seen but I am just guessing.  Do I need to talk to support to get someone to look at things?

Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

Yes. Something intermittent is going on. Get the techs re-involved until it is fixed properly.  Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.




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Regular Visitor

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

I posted the signal levels in the original post. The problem does not happen all the time. I did catch it on time right before it rebooted and the levels were bad and lots of uncorrectables.

I'm at a loss on how to identify what the problem is since it's so random. All the cabling at my home is new and good.
Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet


@MP_X wrote:
I posted the signal levels in the original post. The problem does not happen all the time. I did catch it on time right before it rebooted and the levels were bad and lots of uncorrectables.

I'm at a loss on how to identify what the problem is since it's so random. All the cabling at my home is new and good.

Are you the original poster ? Because the forum name is different.



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Re: T3 T4 timeout issues with gig / SB8200 dropping internet

I am not sure why this ended up being the solution exactly but the fix was to put a MOCA filter on the line coming in to my cable modem and to keep the cable simulator removed. Without the MOCA filter, I was seeing a ton of uncorrected errors and even a large number of corrected. With it installed, I didn’t see any corrected errors (with an exception of the last channel which had over a quarter billion corrected errors) for almost a week.

There was already a MOCA filter on my incoming line to the house and I changed nothing there about that. Is it normal to need a MOCA filter on a modem at all?
Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet


@kill-dash-nine wrote:
(with an exception of the last channel which had over a quarter billion corrected errors) for almost a week.

FWIW, that last channel (other) is the DOCSIS 3.1 OFDM channel for gigabit speeds. There is a known glitch with some makes / models of modem's firmware where the measuring mechanism is inaccurate, so it reads many errors when there really isn't.



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Re: T3 T4 timeout issues with gig / SB8200 dropping internet

Keep an eye on the upstream transmit power levels.

 

The SB2000's modem states it's max power is 51dBmV -- you're riding really close to that in a lot of your posts. (https://arris.secure.force.com/consumers/articles/General_FAQs/SB8200-Cable-Signal-Levels/). This power level typically spikes higher and, most likely, exceeds this spec.

 

This typically points to an issue in the proverial 'line' from comcast's side. Your upstream powerlevels are adjusted by a piece of equipment on in Comcast's hubsuite (Called a CMTS - Cable modem termination system), and tells your modem to increase it's upstream power levels. You cannot see upstream Signal-to-Noise Ratio (SNR) because it's only visible on their hubsuite side. Conversely, they have to tap into your modem to be able to reliably detect the SNR on your downstream. This technology is designed to overcome the immensly long distances of RG6 (coax) that is ran between their fiber 'nodes' and the home. (Hot/Cold expansion, EMF, line noise, etc...).

 

Comcast does this interesting thing where they send a security packet from their service and your modem to verify: you're there, and you're supposed to be there. When they don't receive a response, they disconnect the modem until authentication can be made again. Another words, they're waiting for the security packet from your end to be received on their end... So if you go out of spec on your upload stream, the signal may be too noisy/dirty for the authentication to be understood because your packet was corrupted, so the comcast authentication sends a shutoff command in which your downstream is perfectly capable of receiving (This is a mechanism to prevent theft of their service). Then when your signal is in spec again, it will 'magically come back up' as if nothing happened.

 

It's a nightmare to get fixed because getting an actual line-maintenance ticket opened requires a competent in-home tech who isn't scared to escalate one. (They're terrified to do this because if the issue ends up being something on the home side, the tech gets chastised and 'coached').

Expert

Re: T3 T4 timeout issues with gig / SB8200 dropping internet

FWIW, not quite on some of those points.



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