libnice
The GLib ICE implementation
Libnice is an implementation of the IETF's draft Interactice Connectivity Establishment standard (ICE). It provides GLib-based library, libnice and GStreamer elements.
ICE is useful for applications that want to establish peer-to-peer UDP data streams. It automates the process of traversing NATs and provides security against some attacks.
Existing standards that use ICE include Session Initiation Protocol (SIP) and XMPP Jingle.
There is full API documentation.
Releases at: http://nice.freedesktop.org/releases/ and you can browse the source code at: http://git.collabora.co.uk/?p=libnice.git;a=summary
Mailing list: http://lists.freedesktop.org/mailman/listinfo/nice
Relevant Standards
Farsight is a complete streaming implementation that uses libnice.