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Started Unicast Maintenance Ranging - No Response received - T3 time-out

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Started Unicast Maintenance Ranging - No Response received - T3 time-out

I'm having intermittent Internet issues and support says everything looks fine on their end.  I have a CM1150V Cable Telephony modem.  I thought the issues were my older router, so I decided it was time to upgrade and I bought/set up a Amplifi HD Router which is pretty sweet by the way. But the joy didn't last too long as the intermittent issues returned a few hours later.  Anyway, any time I send a restart to the modem or unplug it to restart it, it works fine for awhile.  However, I'm seeing the follwoing type of errors in the modem log when I'm having issues.

 

Started Unicast Maintenance Ranging - No Response received - T3 time-out;

No Ranging Response received - T3 time-out;

16 consecutive T3 timeouts while trying to range on upstream channel 1;

Dynamic Range Window violation

 

Does anyone have any ideas on what to try or how to get support to look into this further?  I know when I had them on the phone last night, it was working, so obviously everything was working at the time.  They surely have access to these logs as well and can see that I'm having issues.  Anyway, hoping someone might have a suggestion for me.  Thank you.

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Expert

Re: Started Unicast Maintenance Ranging - No Response received - T3 time-out

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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Re: Started Unicast Maintenance Ranging - No Response received - T3 time-out

In additon, I'm seeing the following in the modem log as well

 

RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW

 

 

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New Poster

Re: Started Unicast Maintenance Ranging - No Response received - T3 time-out

Here are the screenshots for the things (I hope) you requested.  Wasn't for sure about the last one though. 

 

https://www.dropbox.com/sh/li4iqqkhlc9rnnc/AACcxu5s3yzB3u2QAnzVuRwma?dl=0

 

Thanks,

 

Mark

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Expert

Re: Started Unicast Maintenance Ranging - No Response received - T3 time-out

There is a wide variance in some of the downstream power levels. And some of the SNR's are too low / out of spec. And the upstream channel at 49 dB is too high, 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

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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Re: Started Unicast Maintenance Ranging - No Response received - T3 time-out

Thanks for your help. I don't have any unneeded/extra splitters.  It comes into the the house, xfinity supplied splitter, then cable is ran to my office, out of the wall into my modem.  Nothing has changed in the last 18 months that I've had this working.  I did update my router yesterday because I thought it might be the issue, apperently it wasn't.  I just don't get it though. I've been running a ping test as well and it's dropping left and right.  However, it seems that a restart of the modem helps it for a little bit, then it rears it's ugly head again.  I don't think it's the modem though.  This only started 2 or so days ago.   Would upstream power level fluctuations not have an impact right away (i.e., modem restart) and cause an impact over time (couple of hours)?  

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Re: Started Unicast Maintenance Ranging - No Response received - T3 time-out

Sure. They may be intermittent. If nothing applies, I suggest that you get a tech out to investigate / correct the problem as stated.

 

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.
Good luck !

 



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