Hello guys,

I installed mod_gsmopen. When testing incoming call, it hangs up with this error message INCOMPATIBLE_DESTINATION.  I understand this is a codec negotiation issue.

Looking at the CDR - the gsmopen presented L16 8000 in the SDP.  By default, FS does early negotiation.  

Snippet of my internal sip_profile:

<param name="inbound-codec-prefs" value="$${global_codec_prefs}"/>

<param name="outbound-codec-prefs" value="$${global_codec_prefs}"/>

<param name="rtp-timer-name" value="soft"/>

<param name="rtp-ip" value="$${local_ip_v4}"/>

<param name="sip-ip" value="$${local_ip_v4}"/>

<param name="presence-privacy" value="$${presence_privacy}"/>

<param name="inbound-codec-negotiation" value="generous"/>

Take note: there is no disable-transcoding parameter which I understand FS is transcodind.

In vars.xml:

<X-PRE-PROCESS cmd="set" data="global_codec_prefs=G7221@32000h,G7221@16000h,G722,PCMU,PCMA,GSM"/>

<X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=PCMU,PCMA,GSM"/>

I tried to add L16 at the end of global_codec_prefs which is unnecessary, isn't it? But it didn't work, too.

Finally, I added L16 in the softphone, it worked.

I have installed gsmopen before and it worked (transcoding) with IP phones. 

Is there anything I may have missed?  I appreciate for any leads.

Thank you, 

/Nandy