[asterisk-biz] SIT Tone Detection

[Leo Ann Boon]

Brett List wrote:
> My SIP Provider (A large major carrier) passes me calls this way. And 
> no, they won't disable early media and provide an appropriate 
> supervision code.
>  
> In fact, all carriers we've tested have transmitted the call this way. 
> Even my cell phone gives me the tri-tone without "connecting"
In my part of the world, the telcos will drop the call immediately and 
return the cause code.

>  
> Yes, chan_sip would need to be modifed. That is the work I am requesting.
The problem with goertzel detection in G.729 is not trivial. Too much 
spectral energy was lost in the transcoding. I'm speaking from 
experience with DTMF detection in G.729.
>  
> For what it's worth, I've attempted to modify chan_sip in the 
> sip_rtp_read func to include adding a dsp with ast_dsp_new, converting 
> to SLINEAR with ast_set_read_format and then passing it to 
> ast_dsp_call_progress. But it doesn't seem to be doing anything at 
> all.. I've been performing my test on G.711.
Your logic is sound. Did you dump out the return values?

Leo