The GIT master branch of Kamailio includes now a new module – rtpproxy-ng. It is designed to be next generation RTP relay control protcol, using bencode as the base for formatting control command. It can be used as a drop-in replacement for old rtpproxy module, but you have to use mediaproxy-ng as RTP relay. Both rtpproxy-ng module and mediaproxy-ng application were developed by Sipwise, main author in the Kamailio devel team being Richard Fuchs.
One of the very appealing features when using rtpproxy-ng and mediaproxy-ng is the ability to bridge WebRTC endpoints to classic SIP phones without any dedicated SBC or media gateway. Mediaproxy-ng is able to decode/encode SRTP to RTP back and forth.