3300 External calls dropping after ~2 minutes?

[MitelInMyBlood]

3300 9.0 UR2
A couple users on a networked (not clustered) 3300 have just begun reporting external calls to their 5340 phones are dropping after a couple minutes or so with the screen message of Timeout. As far as I know no Class of svcs changes have been made. Any ideas?

Original MUG/NAMU Charter Member

 

[MitelInMyBlood]

SMDR shows no answer supervision if that's a clue

Original MUG/NAMU Charter Member

 

[MitelInMyBlood]

More information...
External call across MSDN intermachine trunks between 2 SX2K's then MSDN to a 3300 then IP to the downstream 3300.

Ex: AT&T PRI incoming to SX2K#1, MSDN to SX2K#2, MSDN to 3300#1 then IP to 3300#2. Dest. exten hosted on 3300 #2.

Original MUG/NAMU Charter Member

 

[MitelInMyBlood]

Another call dropped, this one originated on 3300#2. Client dialed an exten hosted on a Cisco CM (rls 5). The routing was 3300#2 IP to 3300#1 then Q.sig to the Cisco. Common denominator would seem to be one of the two 3300s.

Original MUG/NAMU Charter Member

 

[MitelInMyBlood]

Found it!

CL O S setting on the MSDN trunks
Suppress Simulated CCM after ISDN Progress cannot be "yes" on an MSDN span. Must be "no".

This creates weird unspecific problems with intermachine calls, depending on how the call originated upstream. Missing supervision was the clue, but the problem was intermittent. Calls were falling off after approx 3 minutes into the call. Users on the tail end 3300 were seeing "timeout" on their displays.

This actually was a change in the trunk class of service about a week or 10 days ago when working to get forwarded unanswered calls to come back to internal voice mail. The CL O S change fixed the problem w/voice mail at the expense of creating another problem. (as often happens)

There actually was a note about this in the KB article.



Original MUG/NAMU Charter Member