VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Open source Fax server software for inbound / outbound internet Faxing
Unified Communications Server
High performance, production quality STUN server and client library
Baresip is a modular SIP User-Agent with audio and video support
Small and effective program for SIP traces anonymization
Optimized and cross platform SMPTE 2022 FEC library in C, Python, Java
A suite of open-source tools and frameworks for creating SIP apps
The Agispeedy is an AGI Application Server implemention in asterisk
C++ SIP stack based on Chrome source code