Sofia-SIP is a SIP user agent library, compliant with the IETF RFC3261 specification. It can be used as a building block for SIP client software for uses such as VoIP, IM, and many other real-time and person-to-person communication services. The primary target platform is GNU/Linux. Sofia-SIP is based on a SIP stack developed at the Nokia Research Center.
License: GNU Lesser General Public License (LGPL)
Changes:
Basic transaction level load control support has been added. The NAT traversal support in 'nua' has been improved. It is now possible to force rport use at server end, and force routing of requests to a NATed transport address detected by the application. Bugs with SDP offer/answer overlap, BYE handling, and event fetch/poll have been fixed in 'nua'. Bugs with timer handling, RFC2543 dialog/transaction matching, and gray list handling have been fixed in 'nta'. Problems with SDP session handling by 'soa' when media lines are deleted or their type is changed have been fixed.
More...