[SR-Users] Interoperability issues with older SIP clients

[Magnus Nordström]

Hi,

We got interoperability issues with older SIP-clients. When e.g. some 
parameters are included in the SIP header Record-Route the call does not 
get connected. Now we are looking for a solution for that. We are using 
kamailio as SIP-registrar/proxy and would like to know if we can keep 
the call state and rewrite headers that causes interoperability issues. 
We are aware that kamailio is not a B2BUA.

The basic idea would be e.g.:

1. kamailio proxy identifies a call from a modern SIP-client to an old 
SIP-client
2. kamailio send the call to a interoperability module (?)
3. the interoperabilty module removes sip-headers known to cause issues 
and saves them.
4. the interoperabilty module makes sure it is in the SIP signaling path
5. the interoperabilty module send the call forward to the old SIP-client
6. the interoperabilty module stays in path rewriting the SIP-headers. 
The modern SIP-client receives the SIP-signaling as if it was not 
rewritten.

Do you think this is possible with kamailio?

Thankful for any hints or ideas.


Magnus Nordström