VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Open source CSTA library
High performance, production quality STUN server and client library
Enterprise telephony recording and retrieval system
SIP Video Multiconference Media Server with WebRTC support.
GSM air interface
ss7mon an SS7/SIGTRAN signalling monitor
Go to github.com/vlm/asn1c for the latest version.