DTMF RFC2833 transcoding and re-INVITE

Hello,

 

I have a transcoding scenario which don't work for Audio-DTMF<->RFC2833:

 

A call B :

-A Invite Audio-DTMF, SBC add Telephone Event on egress, then B accept RFC2833 (SBC should transcode)

-After 200OK, A re-Invite Telephone-event, SBC re-invite (same sdp), then B accept RFC2833 too.

But, When a Telephone event comes to the SBC from A, SBC don't forward it to B!

 

I could follow this. The transcoding works only if there is no re-Invite to change the DTMF mode.

 

Agent B:

rfc2833-mode preferred

rfc2833-payload 101

 

Agent A:

rfc2833-mode transparent

rfc2833-payload 101

 

Codec policy from A:

allow-codecs *