This feature is new in the Solaris Express 8/04 release.
The Session Initiation Protocol (SIP) server provides support for the deployment of VoIP/SIP services by providing a SIP proxy, registrar, and redirect server. This server is called SER. SER is RFC 3261–compliant and is available from http://www.iptel.org/.
Further information is provided in the /usr/sfw/doc/ser directory and in the man pages in the /usr/sfw/man directory.