Slow uploads - Unicast Maintenance Ranging T3 Time Outs on upstream channel

[tomwyn]

I'm frequently losing internet connection throughout the day, and when there is connection, upload speed can be below 1Mbps when I should get 5Mbps.  Also, my download speed should be 175Mbps, but I get often get only 25Mbps or less.  At night, I often get to 200Mbps down and almost 6Mbps up. 

I found an article on timeouts. 
https://pickmymodem.com/cable-modem-t3-and-t4-timeouts-error-messages-and-how-to-fix-them/

I've tried the following:
1. check for loose cables.
2. remove extra splitters
3.  ordering a power amplifier - will try to see if this helps but it won't come for a while.

What else can I do?  I've called Comcast many times and all the modem and router reboots didn't solve the problem.  I also bought a new router.  One agent said they'll send someone out, but no one called to schedule a visit.  I called back several times and the agent said that Comcast will only send people out if my internet doesn't work at all. 
Thank you for any suggestion.

Here's the information on my Motorola MB7621 DOCSIS 3.0 Modem

   Startup Sequence		 	 
   Startup Step	                Status	Comment	

   Acquire Downstream Channel	603000000 Hz	Locked	
   Upstream Connection.         OK	Operational	
   Boot State	                OK	Operational	
   Configuration File	        OK	d11_m_mb7621_performancepro_c01.cm	
   Security	                Enabled	BPI+	
  ------------------------------
   Connection           Status		 	 
   System Up Time	0 days 01h:36m:02s	 	
   Network Access	Allowed	 	
  ------------------------------
   Downstream Bonded Channels		 	
  
Channel	Lock Status	Channel Freq.   Pwr     SNR   Corrected	Uncorrected
1	Locked	QAM256	32	603.0	2.9	39.6	2	0
2	Locked	QAM256	24	555.0	2.7	40.6	0	0
3	Locked	QAM256	25	561.0	2.6	40.5	0	0
4	Locked	QAM256	26	567.0	2.6	40.3	0	0
5	Locked	QAM256	27	573.0	3.2	39.9	0	0
6	Locked	QAM256	28	579.0	2.1	40.1	2	0
7	Locked	QAM256	29	585.0	2.8	40.0	0	0
8	Locked	QAM256	30	591.0	2.6	40.2	1	0
9	Locked	QAM256	31	597.0	2.8	40.5	2	0
10	Locked	QAM256	33	609.0	2.4	40.0	4	0
11	Locked	QAM256	34	615.0	3.1	40.6	0	0
12	Locked	QAM256	35	621.0	2.7	40.6	2	0
13	Locked	QAM256	36	627.0	3.0	40.7	3	0
14	Locked	QAM256	37	633.0	2.9	40.6	5	0
15	Locked	QAM256	38	639.0	3.4	40.6	1	0
16	Locked	QAM256	39	645.0	3.5	41.0	0	0
17	Locked	QAM256	40	651.0	3.0	42.1	2	0
18	Locked	QAM256	41	657.0	3.3	42.0	2	0
19	Locked	QAM256	42	663.0	2.7	41.9	1	0
20	Locked	QAM256	43	669.0	2.9	42.1	0	0
21	Locked	QAM256	44	675.0	2.4	41.8	5	0
22	Locked	QAM256	45	681.0	2.4	41.7	2	0
23	Locked	QAM256	46	687.0	2.3	41.8	6	0
24	Locked	QAM256	47	693.0	2.1	42.0	0	0
Total	 	 	 	 	 	 	40	0


   Upstream Bonded Channels		 	
  
Channel	Lock  ChanType ChanlID Symb.Rate Freq.  Pwr (dBmV)
1	Locked	ATDMA	8	5120	36.7	49.3
2	Locked	ATDMA	5	5120	17.3	49.2
3	Locked	ATDMA	6	5120	23.7	49.2
4	Locked	ATDMA	7	5120	30.3	49.2
5	Not Locked	Unknown	0	0	0	0.0
6	Not Locked	Unknown	0	0	0	0.0
7	Not Locked	Unknown	0	0	0	0.0
8	Not Locked	Unknown	0	0	0	0.0

Event Log

  Log		 	
  
 Time 	                         Priority 	 Description 
 Fri Apr 24 18:58:35 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 18:58:35 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 18:58:35 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 18:58:35 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:21 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:21 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:21 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:45 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:45 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:45 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:45 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:45 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:05:45 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:34 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:34 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:34 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:58 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:58 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:58 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:58 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:58 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:12:58 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:19:46 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:19:46 2020  	 Critical (3) 	 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:19:46 2020  	 Critical (3) 	 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 
 Fri Apr 24 19:20:10 2020  	 Critical (3) 	 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:60:58:c4;CMTS-MAC=00:01:5c:63:42:66;CM-QOS=1.1;CM-VER=3.0; 

[EG · Accepted solution]

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

[tomwyn]

Thank you, EG, for your review and feedback.

I will check the cables again tomorrow to ensure that I don't have other splitters.

Also, would an amplifier such as these be helpful?
 https://www.amazon.com/gp/product/B0792MVBB3/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B077BCHVWZ/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

[EG]

Amps should only be used as a last resort. They are a *band-aid* type of approach. "Garbage in = even more garbage out". The connection should be fixed in the proper way.

[tomwyn]

FYI - Followup info.
After almost 2 months, Comcast sent a tech to my house.  He checked the cables both inside and outside the house.   He found some issues and replaced a few old connectors with new ones, but the speed did not improve.  He said that there's an internet capacity issue in my area because of too many people on the internet, and Comcast is working to fix that but the work is still on going. 

Also, the upstream power shown on the Motorola Cable Modem was a bit high, and putting in the Arris Amplifier did help to reduce the upstream power level.  The tech told me to keep the Amplifier for now.  He said to get upstream power reduced, Comcast needs to send someone out to fix at the tap on the pole outside my house.
I also tried the CommScope amplifier, but it didn't reduce the upstream power at all like the Arris Amplifier does.

I still have the T3 Time Outs errors on the Motorola modem.