Intermittant One-way call path from BCM

[TelSpt]

We have a BCM50 R5.0 deployed which will intermittantly get one way call path to another office site via H323 trunks.
This is one BCM out of 30 we have deployed worldwide, and one of 2 Rev 5.0s.
All BCM configurations are the same in all switches.
We have G729 set as preferred, but testing with 711 preferred has the same issue.
I can place a test call 10 times to the same DN from this site, using the same phone on the BCM, hitting the same VOIP trunk, Terminating on the same sig server, hitting the same media card in our 81, terminating on the same 3904, and 2 to 3 times, the Codec will set up as 711 in the BCM RTP stream, and one-way voice path.
We allow 711, and have one endpoint that requires 711, so we are not restricting 711, yet when this endpoint sets up a call that negotiates as 711, one way voice path.
When I remove 711 from the available Codecs on the BCM, the call will fail with a Codec rejection error.
Router and switch configs the same on this site as all of our other BCM sites.
I am thinking possible issue with Media card on BCM, although we are using 1140E Phones, and call setup is always G729, but the voicepath will renegotiate from time to time to 711, which should take the media card out of the equation.

 

[pkellow]

The fact this is intermittent could indicate a network problem. I hope the following will help determine if this is a network problem.

Assuming both ends are BCM, on both you could duplicate the problem, and capture the FEPS (voip gateway) log by

http://xx.xx.xx.xx/support/logs/feps.log

where xx.xx.xx.xx is IP address of the BCM.
This will give you an indication of the negotiation. I'm not sure if you will see this on a 50r2 for example, as only certain versions (it will work on a 50r5).

Plus you can capture a LAN trace on both BCMs (again depends on version).

Plus you can MUTE UP DOWN UP DOWN UP MUTE 7 RELEASE to enable port mirroring on the phone and enable a wireshark capture on PC connected to the phone. Repeat on the other phone too.

The signalling may vary from the media path itself. So you would need to capture the LAN trace from both the BCM trunks and the phones, depending on the call flow.

Generally for one way speech issues, always ensure the latest system update (including latest core, feps/iptel, unistim) patches have been applied to the BCM. Also consider any iptel related patches to the cs1k.

Good luck.