Libre is a generic library for real-time communications with async I/O
support. Features are a SIP stack (RFC 3261), SDP, RTP and RTCP, SRTP and
SRTCP (Secure RTP), DNS client, STUN/TURN/ICE stack, BFCP, HTTP stack with
client/server, Websockets, Jitter buffer, async I/O (poll, epoll, select,
kqueue), UDP/TCP/TLS/DTLS transport, JSON parser and Real Time Messaging
Protocol (RTMP).