[VoiceOps] Adtran TA900 timing problems

[My List Account]

Has anyone ever seen this problem?  I have a good number of TA900s and
TA900Es on the other side of a 7206VXR with PA-MC-T3 cards.   Once every few
months SIP accounts in the TA900s that are attached to FXS ports have
trouble passing audio.  It sounds like the audio stream is On/Off about
every 3 seconds.   The only "fix" is to change the timing from the T1 to
internal or reboot the router which effectively does the same thing.

 

It never has an effect on PRI/T1 voice, Hosted PBX behind that router, or
data traffic behind the router.  We never see a problem with other Cisco
routers connected to the same DS3(s) including voice on Cisco 2431-8FXS and
16FXS rotuers.   When the problem happens it will happen to every TA900 or
TA900E at the same time on the same DS3.   It's always a single random DS3
in the same box.

 

I've had countless tickets open with our DS3/T1 Provider over the years and
they always say they see nothing.  Adtran's only solution so far is to
change the timing when it happens.   One tech suggested we just run internal
timing all the time but that seems to only work for 31 days.  I've
completely swapped out the 7200 and the PA-MC-T3 cards.   I've had a JDSU
test set on random DS3s for weeks at a time and never seen a problem.

 

We set up the routers so that the T1 is the Primary and the Internal is
secondary.  I suspect that something happens to the primary clock and it
fails to the internal clock.   When the primary clock becomes available
again the TA900 does not revert back to the T1 clock.  So when we get to
around 31 days the internal timing fails and then the problem with the audio
happens.  

 

 

 

-Richey

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