session border controller (collaboration) (SBC)

As can be seen from the name Session Border Controller( SBC), it is a control unit that is used at the network border between different networks and controls the sessions. It is mainly concerned with Internet telephony( VoIP) sessions. In IP data streams, the signaling data and the media streams or voice data are transmitted separately.

A session border controller consists of the session controller over which the signaling passes, the media controller that establishes the voice connection or media streaming, and the component for providingquality of service, resource access control, and data security.

Session Border Controllers are installed at the transition between two networks. Usually between the secure network of the service provider and the corporate network or between the service provider network and the resident network. When using the Session Initiation Protocol( SIP), the signaling data is sent from the VoIP phone via theIP PBX, to the Session Controller, which transmits it to the VoIP phone of the communication partner. The voice and media data are transmitted from the VoIP phone directly to the communication partner via the media controller.

Session Border Controllers support various encryption protocols such as Transport Layer Security( TLS) and Secure Realtime Transport Protocol( SRTP), transport protocols such as the Transmission Control Protocol( TCP) and the UDP protocol, transcoding according to G.711, the call numbering scheme according to E.164 and the SIP protocol and the QSIG protocol for signaling.