Session Border Controller

A Session Border Controller or SBC is a network device that is used to secure and protect SIP-based voice over IP network services.

VoIP communication differs somewhat from more conventional data communications and requires specialized treatment when applying security mechanisms at the network edge. SBCs are specially designed to ensure that VoIP sessions are secured while avoiding the disruption of their services that a conventional firewall may cause.

SBCs can be standalone devices or can be incorporated into firewalls or into routers. Cisco delivers SBC services on its Cisco Unified Border Element (CUBE) device. In the past, the SBC was part of the CUBE-SP offering which was the service provider SBC, but this has been End of Life for some time.