[asterisk-users] One-Way-Audio After placing call on hold

[Matt]

I (and some others) are having an issue with placing calls on hold.

Our setup is as follows:

IAX2 or SIP terminator/originator ---> asterisk box ---> SIP Phones

I have tried asterisk verison 1.0.9, 1.2.6 and 1.2.12, and all have
the same issue.

When I place a call on hold that has come in a PSTN channel (through a
PRI and a Digium card) everything is fine.  When I place a call on
hold that has come in or gone out an IAX2 or SIP terminator or
originator, when I pick the call back up often there is one-way-audio
(I can hear the caller, but the caller can not hear me).

I have attached a packet capture of the situation, and as you can see
at about packet #3803 the audio goes one way.   Can anyone enlighten
me as to why this is happening, and why asterisk is no longer sending
audio back to the terminator?   I would like to get this fixed,
obviously.

(This file was a tcpdump, and can be opened in ethereal/wireshark)

EDIT: Packet capture at following address:
http://hecate.chilitech.net/~matth/zootdump.cap