An engineer is reviewing a SIP syslog on a TC software-based endpoint. Which area in the syslog indicates the start of the SDP session?

The a= field represents SDP attributes such as codec mappings (rtpmap) and media direction (sendrecv), and appears at both session and media levels rather than marking the session start.

The v= field carries only the SDP version number (always the value 0) and is a protocol framing field, not an indicator of session content or negotiation parameters.

The b= field in SDP (RFC 4566) specifies the proposed bandwidth for the session at the session level, and in Cisco TC software syslogs this field serves as a recognizable marker for the session description block. Identifying b= within the syslog output allows an engineer to locate the session-level SDP parameters and understand the bandwidth constraints negotiated during call setup.

The m= field marks the beginning of a media-level description (audio, video, etc.) and follows session-level fields, so it indicates a media stream block rather than the overall SDP session.