I am running a FreeSwitch 1.10 (built Debian Packages from the GIT-Branch due to some codec issues; AMR/AMR-WB is only available, if the respective libraries are present on the system).

I am using FreeSwitch in the most simple configuration: FreeSwitch is acting as a (transcoding) B2BUA with only a single peer (Kamailio, which does the further distribution, Sofia Config attached), so my dialplan is straight forward and contains a single action:

<action application="bridge" data="sofia/internal/${destination_number}@${loadbalancer}"/>

Here  is, what I've noticed and where I am unsure, how to fix this:

1) Call from A is sent to FreeSwitch, with Codecs AMR and AMR-WB

2) Call is leaving FreeSwitch towards B, offering Codecs AMR, AMR-WB, G722, G711, ... B-Party is selecting G722, as it does not support AMR or AMR-WB,

3) Call is connected to A on AMR/AMR-WB and to B using G722

- so far, everything is fine -

Now the following happens:

4) A puts the call on hold, so a INVITE with according SDP is sent to FreeSwitch

5) FreeSwitch itself sends an INVITE to B indicating the recognized "Hold" with according SDP, however now this INVITE only contains AMR-WB, which was initially offered to B, but which was never responded or even indicated support for (!?!??!)

I can hardly believe, I am the first one to see this. Does anyone know where or what to look for and what might have gone wrong here?

Thanks,

Carsten

P.S.: The first mail didn't go through, as I added my Sofia Config.... without any notice.