Round Trip Delay Timeout Expiry

[PhaseJitter]

We have a site that is experiencing random call drops on any of 5 VoIP trunks. An entry in the SysMonitor log seems to preceed the drop by a few millisecs...
PRN: H245RTDSE --- Round trip delay timeout expiry, clearing call

Network seems good, low latency, and callers report that call quality normal before call is dropped. Effecting approx 5-10% of voip calls. When disconnects do occur, usually call is < 90 sec duration. This is a IP 406 version 4.0(10) Nothing new in our setup. Has anyone seen anything similar? Thanks for any suggestions.

 

[Westi]

4.0 sucks, go with 4.2 or 4.1
sorry can't give any more suggestions then that.

Joe W.

FHandw., ACS

If you can't be good, be good at it!

 

[TomMills]

that is good advice

 

[scottjc]

I had something similar on one of my sites where SCN calls dropped after 90 seconds exactly.

I had to upgrade to 4.2 and turn off H225/245 inspection on my firewalls

It’s been mentioned on tech tips before but this might help.

Also someone discovered that if you press and digit during the call (send DTMF) then the call will not drop.