OpenSIPS

OpenSIPS is a GPL implementation of a multi-functionality SIP server that targets to deliver to a high-level technical solution. OpenSIPS is a free software implementation of the session inititation protocol (SIP) for voice over IP (VoIP) that can be used to handle voice, text and video communication. OpenSIPS is intended for installation serving thousands of calls. It contains the performance, security and quality to be used in professional SIP server platforms.