Hello, First of all, i apologize for double posting on Kamilio users and sr-dev. I wrongly posted Kamailio users mailing list. We're making initial modifications to rtpproxy to support high channel capacity transcoding and encryption. At this point we want to get some general idea of the scope of changes needed for rtpproxy and Kamailio... so we're starting with small steps. We've been studying rtpproxy source and our current thinking is to add a sub-structure to the existing rtpp_session structure (defined in rtpp_session.h). The new sub-structure would include: -encryption options (type, key length, salt size, type of key mgt protocol, etc) -encode / decode options (type, VAD/CNG, VIF size, etc) Any comments or advice on this approach appreciated. Not sure whether to start a separate thread, but also there is the issue of what changes are necessary to Kamailio to support sending updated commands to rtpproxy. Would modifying Nathelper alone be sufficient? Thanks and Regards, Vikram. PS : I'm posting on Kamailio's mailing list because it seems that both Kamailio and rtpproxy developers closely follow this list.