Continual "No Ranging Response received - T3 time-out"

[NoTick]

Hello --

I keep getting "No Ranging Response received - T3 time-out" errors on my Arris SB6190. I've placed a brand new SB6190, as well as an older Motorola SB6141, and all have had the same issue. (Both Arris SB6190's were brand new out of the box). I'm using commercial grade Ubiquiti networking equipment, and have eliminated them as the problem, as the problem happens when DCHP directly to the modem. This issue has been happening consistently since I first moved in to my home (Feb 2018).

My downstream signal levels are good. SNR downstream is also good.

Upstream has always been an issue. I was observing peaks where the CMTS would crank my modems upstream output level beyond 52 (thus out of spec) and the modem would timeout. 

This prompted me to remove all splitters between my modem and the Comcast Tap. The RG-6 cable going to the tap is directly connected to the grounding block from Comcast -- so it's directly connected to the proverbial 'pipe'. The ends are terminated with the best compression fittings in the industry and brand new.

Whenever the line comes under load (E.g. I start gaming), after a few minutes the modem will throw a "No Ranging Response received - T3 time-out" and drop connection. Looking at my logs, I always observe one or more of the upstream power-levels spiked higher than normal, telling me the CMTS at the other side of the pipe cranked my levels for some reason (presumably bad SNR in the up-stream connection).

Below is my signal readout (down levels are high because I'm directly connected to the 'Pipe' as stated previously.)

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Corrected	Uncorrectables
1	Locked	256QAM	27	627.00 MHz	4.20 dBmV	40.37 dB	5	45
2	Locked	256QAM	34	441.00 MHz	6.40 dBmV	40.37 dB	0	0
3	Locked	256QAM	35	447.00 MHz	6.10 dBmV	40.37 dB	0	0
4	Locked	256QAM	36	453.00 MHz	6.40 dBmV	40.37 dB	0	0
5	Locked	256QAM	37	459.00 MHz	6.40 dBmV	40.37 dB	0	0
6	Locked	256QAM	1	465.00 MHz	6.30 dBmV	40.37 dB	0	0
7	Locked	256QAM	2	471.00 MHz	6.10 dBmV	40.37 dB	0	0
8	Locked	256QAM	3	477.00 MHz	6.20 dBmV	40.37 dB	0	0
9	Locked	256QAM	4	483.00 MHz	6.50 dBmV	40.37 dB	0	0
10	Locked	256QAM	5	489.00 MHz	6.50 dBmV	40.37 dB	0	0
11	Locked	256QAM	6	495.00 MHz	6.50 dBmV	40.37 dB	0	0
12	Locked	256QAM	7	507.00 MHz	6.30 dBmV	40.37 dB	7	0
13	Locked	256QAM	8	513.00 MHz	5.90 dBmV	40.37 dB	0	0
14	Locked	256QAM	9	519.00 MHz	5.90 dBmV	40.37 dB	16	0
15	Locked	256QAM	10	525.00 MHz	6.00 dBmV	40.37 dB	0	0
16	Locked	256QAM	11	531.00 MHz	5.70 dBmV	38.98 dB	0	0
17	Locked	256QAM	12	537.00 MHz	5.60 dBmV	38.98 dB	0	0
18	Locked	256QAM	13	543.00 MHz	5.60 dBmV	40.37 dB	3	0
19	Locked	256QAM	14	549.00 MHz	5.70 dBmV	38.98 dB	0	0
20	Locked	256QAM	15	555.00 MHz	5.90 dBmV	38.98 dB	0	0
21	Locked	256QAM	16	561.00 MHz	6.30 dBmV	38.98 dB	0	0
22	Locked	256QAM	17	567.00 MHz	6.50 dBmV	40.37 dB	5	0
23	Locked	256QAM	18	573.00 MHz	6.90 dBmV	40.37 dB	11	0
24	Locked	256QAM	19	579.00 MHz	7.10 dBmV	40.95 dB	10	0
25	Locked	256QAM	20	585.00 MHz	7.00 dBmV	39.90 dB	10	0
26	Locked	256QAM	21	591.00 MHz	6.70 dBmV	39.90 dB	0	0
27	Locked	256QAM	22	597.00 MHz	6.10 dBmV	39.90 dB	0	0
28	Locked	256QAM	23	603.00 MHz	5.30 dBmV	39.50 dB	0	0
29	Locked	256QAM	24	609.00 MHz	4.90 dBmV	39.50 dB	0	0
30	Locked	256QAM	25	615.00 MHz	4.60 dBmV	38.90 dB	7	0
31	Locked	256QAM	26	621.00 MHz	4.10 dBmV	39.20 dB	0	0
32	Locked	256QAM	28	633.00 MHz	4.20 dBmV	39.20 dB	0	0

Upstream Bonded Channels
Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	4	5120 kSym/s	16.60 MHz	35.50 dBmV
2	Locked	ATDMA	3	5120 kSym/s	23.00 MHz	35.00 dBmV
3	Locked	ATDMA	2	5120 kSym/s	29.40 MHz	35.50 dBmV
4	Locked	ATDMA	1	5120 kSym/s	35.80 MHz	35.25 dBmV

How do I get the upstream line-levels and SNR inspected at the plant? An in-home tech cannot do that.

[EG]

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.

[NoTick]

I totally understand.

I feel like cutting out the middle man would be less timeconsuming in this instance. I, unforutnately, don't have hours to commit to being available away from work for a Tech to make their visits, especially considering they're going to charge a fee for the visit just to escalate to an engineer at the plant anyways.

[NoTick]

Here is an example of what I am talking about. A random spike on Upstream - almost outside of spec. Channel 3 spiked 12.75 dBmV.

Modem is connected directly to Comcast's ground block at the houses demarc.

Channel 	Lock Status 	US Channel Type 	Channel ID 	Symbol Rate 	Frequency 	Power
1	Locked 	ATDMA	4	5120 kSym/s	16.60 MHz	39.50 dBmV
2	Locked 	ATDMA	3	5120 kSym/s	23.00 MHz	39.75 dBmV
3	Locked 	ATDMA	2	5120 kSym/s	29.40 MHz	48.25 dBmV
4	Locked 	ATDMA	1	5120 kSym/s	35.80 MHz	38.75 dBmV

[NoTick]

Have a tech coming on sunday (8/18).

Here's to hoping I can convince them to open a line-maintenance ticket.

[NoTick]

Comcast Tech visited today.

After standing in my office and watching the modem reset itself as I explained the issues I've been having and my observations, they were unable to find an issue within my home, as expected. They were reading +10dB on their pipe, but we were seeing +7 to +8dB on my modem's downstream, with an SNR of over 39dB. My upstream power levels typically sit between 33dB to 40dB from a weeks worth of observations. At times they peak in the mid to high 40's, which is concerning, but not out of spec. Because of the signal drop between the pipe and my modem, the tech wanted to assume it was the cable ran between the DMARC and my modem.  After educating the tech on the signal loss that a MoCA filter can cause in the ingress, and his supervisor confirming this, they replaced my MoCA filter/grounding block at the DMARC of the house, and ran a new line... Just in case.

Apparently, according to the tech (after spending 10+ minutes on the phone with his supervisor who told this to him), there were 7 signal issues within my neighborhood for the 'Signal team/Noise Patrol'. The exact words used by the tech were "It's a plant issue - it's not your house". This morning alone, there were 5 tech visits to my neighborhood including mine.

The most concerning thing the tech shared: a home a few houses down has a SNR near 0, and it's been an ongoing issue for over a month. I saw this home with a brand-new shielded RG6 between the ground-box and their house that's been there for about this same duration, unburried, so I can corroberate that this is probably true. It was burried only a week or so ago. This is very, very troubling to me, especially considering this issue is still ongoing for this customer, and hasn't been corrected.

Am I to expect a multi-month issue to continue at my home, as well?

[NoTick]

Fun fact - since the tech has left, the issue has persisted (you can see the logs below). I see random losses of connection, yet the modem never indicates (via status lights) that it's lost connection. Other times, it fully loses sync and resets entirely.

https://i.imgur.com/LF3Ex7T.png  <--- LOGs

https://i.imgur.com/F5YNXWI.png  <--- Signal

[NoTick]

Another note...

Since the tech left (only changes: new line between House and Comcast - new MoCA filter):

Even with the intermittent connection interruptions, my upload speeds typically sat between 10-11Mbps when using standard speed tests.

Now it's struggling to get over 2-3Mbps  upload.

Something is immensly wrong.

[NoTick · Accepted solution]

Noticed the tech left the lawn junction boxes disassembled (lids laying in my lawn, the rigid/coax and taps fully exposed).

Went to put them back on and noticed the tap my house line connects to had one of its terminals unoccupied and was not terminated. I properly terminated it, and suddenly I haven't had a single modem issue in 12 hours.

Who knew following CATV install 101 would eliminate signal issues.

[darkpenn]

I just want to say thank you for continuing to update this post. I am seeing almost the same exact thing at my house. Gonna see if I can find an unterminated end outside.