The following Avaya SBC features support the recording solution:

• Initiation, modification, and termination of recording session from the SIP Recording Server (SRS) during the recording session.

• Early media clipping avoidance during session setup.

• Wave file played to indicate that the session is being recorded.

• Alternate routing for recording sessions with Round Robin load balancing.

  When a recording session starts, Avaya SBC starts a timer. When the timer expires, Avaya SBC triggers alternate routing mechanisms. Avaya SBC also uses alternate routing mechanisms after receiving the following messages from the recording server: 408,480,486,488, 500, and 503.

• High Availability for the recorder media stream and metadata sent to the Recording Servers.

• Recording Server routing.

  Avaya SBC communicates with a cluster of Recording Servers. You must administer a URL for each Recording Server in the cluster. Avaya SBC sends an INVITE message to the Recording Server. When Avaya SBC sends the Contact URI with the feature tag +sip.src in the INVITE message to the SRS, the SRS identifies a recording session.

• Metadata elements to identify media streams from SRC and SRS.

  Avaya SBC provides the following metadata elements:

  Metadata element	Supporting parameter
  Call identifier	UCID
  Session Identifier	sdp session id
  Participant Identifier	PAI
  Stream Identifier	Label on media stream
  Stream direction	send, recv and inactive
  Timestamp for resynchronization	NA

• No controls from the trunk side of the recording sessions.

  Avaya SBC uses only the controls specified from Avaya SBC and at the recording server.

• Unique labels for media streams to identify the media stream for participants in the recording session.

• Security options.

  Avaya SBC supports an SAVP profile for SRTP sessions and an AVP profile for RTP sessions. Avaya SBC supports TLS and TCP connection. ACR supports TCP connection with SIP uri scheme using RTP/AVP and SAVP profile.

  Note:

  For SIPREC, Avaya SBC supports SRTP only with hmac80, because ACR does not support any other cryptographic algorithm.

• REFER handling and redirection supported in recording scenarios.

• SIP recording in translator mode. Avaya SBC receives media streams and relays them to the Recording Server. Avaya SBC does not change any data in the media streams.

In addition, Avaya SBC provides the following features:

• Support for full-time, selective, and continuous recording.

• Support for call termination on recording failure.

  When Avaya SBC initiates a session towards every configured recording server, there can be scenarios when none of the servers respond. In such scenarios, Avaya SBC can terminate the session that is initiated or in progress towards the calling or called party. Call termination on recording failure is not supported for remote worker calls.

• Support for recording a remote worker to remote worker call.

• Support for recording in case of downstream forking.

  If Avaya SBC received multiple forked dialogs, the first dialog received with early media is recorded. Subsequent early media in forked dialogs is not recorded. For final answer, the media stream between the calling and final answered party is recorded.