[Kamailio-Users] SIP-T: Multipart SDPs, ISUP parsing, etc

[Daniel-Constantin Mierla]

Hello,

On 09/03/08 19:10, Kristian Kielhofner wrote:
> Hello everyone,
>
>   Feel free to set $OSSPROXY to whatever you like =
> Kamailio/OpenSIPS/OpenSER (for those of you who can't let go).
>
>   $OSSPROXY is my favorite SIP toolkit.  In addition to being an
> excellent proxy and registrar it serves as a platform to do SIP
> mangling and wrangling.  With that in mind let me propose a crazy
> idea...
>
>   How hard would it be to get $OSSPROXY to be able to parse what is
> commonly referred to as SIP-T (RFC 3372)?  I understand $OSSPROXY has
> no business getting too involved in the SDP but I feel it makes sense
> in some instances (like this one).  What if I want to make a routing
> decision based on an encapsulated ISUP parameter of some sort?  Who
> knows what it could be!?!?  Maybe there are some other uses but that
> makes the most sense and seems to be the most practical.  It should be
> possible to develop an $OSSPROXY module to:
>
> - Use the SDP parser to find the ISUP SDP part:
>
> http://www.kamailio.net/dokuwiki/doku.php/development:sdp-parsing
>
> - Pass that part into a "real" ISUP parser (if necessary).  I couldn't
> seem to find the perfect library but perhaps something like this could
> work:
>
> http://www.openss7.org/isup.html
>
> - Make the ISUP parameters available via AVPs, pseudo variables, etc
> for use in the $OSSPROXY script.
>
>   I don't really have a need for this but it seems like it could be
> cool.  Am I nuts?
>
>   
I would expose the body as a dynamic structure, so components will be 
accessible in the script, e.g. (naming schema just for example),

if($body(0=>content-type)=="application/sdp")
{
    if($body(0=>m=>type) == "audio")
    {
    }
}

Based on the available content type parsers (sdp, isup), the structure 
has different attributes.

Cheers,
Daniel


-- 
Daniel-Constantin Mierla
http://www.asipto.com