scope:

This Standard defines the Session Border Controller (SBC) functions and requirements that reside within a service provider's network. The functions performed depend on the interface supported.

The following interfaces are supported by an SBC located within a Service Provider's Network:

• To another Service Provider;

• To an Enterprise Network;

• To a Transit Network;

• To a Residential Customer Network;

• To an Access Network;

• To an Application Network.

This Standard defines the SBC functions and requirements for the above interface types. The physical realization of the functions will vary depending on implementations and deployments. The unification and/or distribution of the functions will depend on scale, operational and application needs.

The SBC functions include (but are not limited to):

• Access admission and resource policy enforcement

• Firewall

• Topology hiding

• Traffic monitoring and shaping

• QoS marking and mapping

• Priority marking and mapping

• Protocol normalization and or repair

• Protocol interworking (e.g., SIP and H.323)

• IPv4/IPv6 interworking

• Signaling transport protocol interworking

• NAT traversal

• Transcoding and DTMF interworking

• Media and/or call/session control signaling encryption and decryption

• Support of Lawful Intercept

• Support of Emergency Telecommunications Service (ETS)

• Authentication, Authorization and Accounting (AAA)

• Privacy and Identity control

• VPN bridging or mediation

• Protect against DoS attacks

• User/endpoint registration.

The main sections of the document are:

• Section 6, Deployment Area: defines logical relationships at the call/session control and bearer/media layers.

• Section 7, SBC Functions: defines the functions related to the call control signaling path and media path.

• Section 8, SBC Requirements: define the requirements on the functions independent of the physical realization.

• Section 9, Composition of SBCs: provides the rationale for SBCs.

• Section 10, Mapping to ATIS NGN Architecture: identifies the architecture functional entities that perform SBC functions for the media and signaling paths.