Ubigate iBG2016 Configuration Guide© SAMSUNG Electronics Co., Ltd. 337CHAPTER 3. SIP Gateway ManagementIntroduction to SIP Gateway FeaturesInformation about SIPSIP is a simple, Text-based protocol that uses requests and responses toestablish communication among the various components in the network and toultimately establish a conference between two or more endpointsSIP Capabilitiesy Determines the location of the target endpoint− SIP supports address resolution, name mapping, and call redirection.y Determines the media capabilities of the target endpoint− SIP determines the lowest level of common services between the endpointsthrough Session Description Protocol(SDP). Conferences are establishedusing only the media capabilities that can be supported by all endpoints.y Determines the availability of the target endpoint− If a call cannot be completed because the target endpoint is unavailable,SIP determines whether the called party is connected to a call already ordid not answer in the allotted number of rings. SIP then returns amessage indicating why the target endpoint was unavailable.y Establishes a session between the originating and target endpoints− If the call can be completed, SIP establishes a session between theendpoints. SIP also supports mid-call changes, such as the addition ofanother endpoint to the conference or the changing of a mediacharacteristic or codec.
