A SIP server is a server that manages and controls IP telephone services using SIP (Session Initiation Protocol). A SIP server provides the following main features.
Proxy server: Relays SIP requests and SIP responses
Registrar server: Receives address information for devices on the IP network and registers them to a database.
Redirect server: Returns address information for SIP requests
A SIP server allows you to specify the destination by SIP user name or fax number.
Recipient Designation Example
SIP user name: 1111
A: SIP Server