Flexisip
Flexisip is a SIP proxy server implementation compliant to RFC3261, written in C++ 11.
Kamailio
Kamailio® (successor of former OpenSER and SER) is an open source SIP server released under GPL, able to handle thousands of c ...
Asterisk
Asterisk is free software that transforms a computer into a communication server. Asterisk lets you build applications like PB ...
FreeSWITCH
FreeSWITCH is a scalable open source cross-platform telephony platform designed to route and interconnect popular communicatio ...
Yate - Yet Another Telephony Engine
Yate is a softswitch (concept of separating the network hardware from network software). It supports VoIP protocols: H.323, ...