What is the SIP Express Router?

The SIP Express Router is an open-source SIP proxy server compliant to the IETF RFC3261 SIP protocol. It is targeted at large volume applications.

With its small footprint the SER is extremely fast to forward requests and can handle thousands of users in a single server. It is being used by large voice-over-IP providers and for embedded IP PBXes with very low processing power. Their interoperability with several sorts of equipment makes them a de facto standard.