Conventions for the use of the Session Description Protocol (SDP)for Digital Circuit Connections
This document describes conventions for using the Session Description Protocol (SDP) for controlling digital circuits. These conventions describe - circuit addressing conventions for use on the SDP 'c=' line - content of the 'm=' line(s) for digital circuits - attributes to convey the parameters contained within the Bearer Capability, Low Layer Compatibility, and High Layer Compatibility Information Elements of ITU-T Recommendation Q.931. These conventions have been defined for use in media gateway control, particularly in support of NAS operation, but may also be used by IP-based call signalling schemes (SIP, BICC) to control media exchange over digital circuits.