mini SIP Server is a SIP Server or VOIP server for Windows systems. mini SIP Server is based on the SIP standard which is an open standard. There are so many SIP phones (software or hardware), you can choose anyone you like without vendor lock in. It is very easy to setup and manage your own VOIP system. In fact, you can use MSS to deploy a basic VOIP network in one hour. It features ring group, caller-ID rewriting, auto attendant, messages waiting indication, and direct inward system access.