Hi list,
I have an issue in my Freeswich in SBC mode.

It's a call from Freeswitch to my endpoint, my endpoint answer G729, after this 200OK, my end-point re-invite in G711A, and my freeswitch say: "Codec G.729 decoder error".

Ex :
1) SIP Provider ----INVITE(PCMA, G729)-----> FS ----INVITE(PCMA, G729)-----> End-point
2) SIP Provider <-----(200 OK G729)------ FS <------(200OK G729)------ End-point
3) FS <------(Re-INVITE PCMA)------ End-point
4) FS Error "Codec G.729 decoder error" in logs

In fact, it's something like http://jira.freeswitch.org/browse/FS-3739, but the patch doesn't seem to work in our situation.


My freeswitch's conf:
sip_profile TOTO: 
    <!-- dtmf method -->
    <param name="dtmf-type" value="rfc2833"/>

    <!-- Payload type if the DTMF method is rfc2833 -->
    <param name="rfc2833-pt" value="101"/>

    <param name="inbound-late-negotiation" value="true"/>

    <param name="inbound-codec-prefs" value="PCMA,G729,PCMU"/>

    <param name="outbound-codec-prefs" value="PCMA,G729,PCMU"/>


Diaplan TITI:
<action application="export" data="codec_string=${ep_codec_string}"/>
<action application="set" data="hangup_after_bridge=true"/>
 <action application="set" data="ignore_early_media=true"/>
<action application="set" data="inherit_codec=true"/>
<action application="export" data="t38_passthru=true"/>
<action application="export" data="suppress_cng=true"/>
<action application="bridge" data="
                                        {
                                                sip_invite_params=user=phone,
                                                sip_cid_type=none,
                                                ignore_display_updates=true,
                                                sip_renegotiate_codec_on_reinvite=true,
                                        }
                                        sofia/gateway/${distributor(LISTTMP ${sofia(profile TITIPRO gwlist down)})}/${numberdest}"/>


We choosed to use inbound-late-negotation with inherit-codec because of our t38_passthru option (as described here in FS wiki, I don't exactly remember where)

To resolve this problem, we tried to find how to make FS forward the Re-INVITE received on B-Leg to the A-Leg, but we didn't found any solution... If someone have an idea, it would be great ! ;-)


Thanks a lot,
Bien cordialement, 
Best Regards, 

Kevin MATHY