Frequent Visitor
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8 Messages
No Ranging Response - T3 Timeout, Intermittend Connection Drops
Hi,
I have an Arris SBG10 Modem/Router combo. I've used this unit since Dec 2019 on Comcast service with no issues prior to this week.
I'm having intermittent connection issues with my Xfinity service. Called Xfinity and they noted that my upstream signal power levels were lower than what my modem requires. Currently they are at ~42 dBmV per channel and the spec for the modem is 45 dBmV. Nothing was done to correct the signal levels. I've tried a hard reset on the modem to confirm that it's not a config issue on my end as well.
Downstream is in between 7.5 and 8.2 dBmV and the SNR is 40.37.
About a month ago, a Comcast tech rewired the wall plate. When the service was installed at my new residence (6 mos ago or so), a new line was run to the home. I've had no issues like this up until now.
I've noticed an abundance of "No Ranging Response received - T3 Timeout," "Ranging Request Retries Exhausted," "Unicast Maintenance Ranging attempted - No Response," and "RCS Partial Service" entries. These seem to coincide with my intermittent connection failures, where the modem effectively restarts. Both Wifi and ethernet go down and I'm unable to access the gateway temporarily.
I've attached screen shots of the logs and the CM status below.
I'm at a loss as to how to fix this. The connection drops are impossible to predict and are quite infuriating. Is this something that Comcast can fix? Is this an issue with the CMTS or some further upstream point?
EG
Expert
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110K Messages
4 years ago
Can't see your pics. Since you are a new poster, they need to be approved by a Forum Admin. That could take some time. In the interim, you could try hosting them at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to them here.
Or copy all of the text of the status page and paste it into the body of your next post here.
Also, post the error log entries in their entirety.
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Dezenzerrick
Frequent Visitor
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8 Messages
4 years ago
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Dezenzerrick
Frequent Visitor
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8 Messages
4 years ago
https://imgur.com/a/bTvKENX Here's a link to today's issues. I am unable to download the logs, or at least I don't know how just yet. I will continually update this album with new events.
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Dezenzerrick
Frequent Visitor
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8 Messages
4 years ago
https://imgur.com/a/bTvKENX
Updated the album for today's issues. Notice the number of "corrected" and "uncorrectables" for the FEC. That seems so much higher than expected for 2 days of run time
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Dezenzerrick
Frequent Visitor
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8 Messages
4 years ago
2 T4 Timeouts in about 30 minutes. Basically at my wits end with this. More T3 and RCS errors than I can keep track of. https://imgur.com/a/bTvKENX
Is this CMTS? Is this headend? Is this an issue with my own cables? Honestly have no idea how to proceeed with this.
Edit to add some more backstory: Comcast installed a line here last october and things have been fine up until now. New line to the home, new box, etc.
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CCAshley1
Official Employee
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746 Messages
4 years ago
Hi @Dezenzerrick! Thank you for reaching out to us here on Xfinity forums. I apologize for the service issues you are going through at this time. Ive been there and know it is past frustrating and you just want to have the issue resolved. Are you connected to the modem wired or wifi? Have you tried swapping your modem just to see if t the connection remains steady with a different modem?
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EG
Expert
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110K Messages
4 years ago
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 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
Also check the coax cable for any damage such as cuts / nicks, 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.
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Dezenzerrick
Frequent Visitor
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8 Messages
4 years ago
Figured I'd post an update.
Comcast tech came out a couple days ago and inspected the line and all connections. No significant noise leaks found, all connections into the house and at the termination end are good. He removed a splitter (this was installed but comcast in January) and added some sort of reducer in the box. It knocks down the upstream power level by 9 dbm.
He told me the logs from the modem don't really help and that modems spit those out errors frequently, honestly not sure if that's true. I'm going by the FEC counter and it's still going nuts.
I'm still having these issues, even as we speak.
To answer some questions:
I'm connected via ethernet and wifi, this issue affects everything. Enough T3 timeouts cause the modem to reset entirely, and a single T4 will do the same. At the times the T3 and T4 timeouts occur, as well as the RCS Partials issue, I lose connection but the modem stays on. The FEC tries to correct some of the packets but ultimately fails and the "uncorrecteds" counter goes up.
What I'm going to try tomorrow is moving my modem into the garage where the coax comes in from the box outside. I'll update then if this issue continues. I'm also considering renting a modem from Xfinity for a short while to see if that's the issue.
Thanks for the tips!
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