Visitor
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3 Messages
No Ranging Response received - T3 time-out every 30 minutes
Hi,
I see the T3 time-out every 30 minutes (or shorter), which causes a loss of connection. Once the restart has completed and I am reconnected, the connection is stable from time to time but has been dropping more consistently over the past month (July 2023). I see the following message in the event log after the modem comes back up:
No Ranging Response received - T3 time-out;CM-MAC=[REDACTED];CMTS-MAC=[REDACTED];CM-QOS=1.1;CM-VER=3.1;
This is my first attempt at getting support. I have researched this issue through multiple reports online and I am following this Xfinity thread, which appears to be a similar issue.
The modem is cabled directly from the wall, no additional splitters (I suspect there is a master splitter outside in the cable box).
Connection details:
Cable Modem is: ARRIS S33
Cable Modem connection details:
Accepted Solution
EG
Expert
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110K Messages
2 years ago
This may or may not be the root cause of the problem (YMMV) but it should be addressed regardless.
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, latency problems, and the un-bonding of channels.
In an 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 5-1000 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.
Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.
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.
Good luck with it !
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user_aca125
Visitor
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3 Messages
2 years ago
Thank you EG, for your response!
I moved the cable modem to a different cable outlet in my house and noticed that the move reduced the highest upstream power by around 2dBmV.
Does this upstream power still look too high?
Moving the cable modem (which reduced the upstream power) seems to have had a positive impact on the stability of my internet connection since it reduced the T3 and T4 timeouts to only being logged two times today. It also appears that even though these timeouts occurred, they did not cause a dropped internet connection.
You reminded me that I do have a Commscope RF amplifier (Part Number: CSAPAE615V500) in my cable box that an Xfinity cable technician installed 4 years ago to improve my signal. Could this equipment be something that affects upstream power? As a test, I removed the power being injected into the amplifier within the cable box (through a Commscope CSHMPI power inserter/splitter), but this change immediately caused my internet connection drop and I could no longer communicate with the cable modem.
I will continue to monitor the internet stability tomorrow and report back.
Thanks again!
(edited)
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EG
Expert
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110K Messages
2 years ago
Quite welcome. There's some wiggle room now. It should be OK as long as the signals remain relatively stable. Hope things hold up for you ! Good luck with it !
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user_aca125
Visitor
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3 Messages
2 years ago
This issue appears to be resolved. The T3 and T4 timeouts are still occurring, but they are not knocking me offline and are not occurring as frequently. Thanks again EG for your help.
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EG
Expert
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110K Messages
2 years ago
@user_aca125
My pleasure ! Thanks for circling back here ! Best of luck with it !
(edited)
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EG
Expert
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110K Messages
2 years ago
Marked "Solved" thread now being closed.
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