[SR-Users] Interoperability issues with older SIP clients

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