Matrix reference homeserver
5G/4G Cellular Security Live Linux OS for SDR, Baseband Auditing & Tel
VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Open source CSTA library
Browse on Tor / i2p - Anon p2p Chat / FileTx, Conf / Video VoIP
ICTCore: Unified Communications Framework for web developers
A beautiful SMS messenger for Android
CM8200/SB8200
open5g is an open source implementation of the 3GPP 5G specifications.
High performance, production quality STUN server and client library
A Better PBX For Your Business
Enterprise telephony recording and retrieval system
ERP, IP PBX, Accounting, CRM, Time tracking, and etc.
SIP softphone
H.323 Gatekeeper for VoIP and videconferencing
SIP Video Multiconference Media Server with WebRTC support.