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SIPREC WG 1July 30, 2010
SIP Call Control - Recording Extensions
draft-johnston-siprec-cc-rec-00
Alan Johnston <[email protected]>
Andrew Hutton <[email protected]>
SIPREC WG 2July 30, 2010
Introduction
• Draft proposes mechanisms to address some requirements from draft-ietf-siprec-req-00– REQ-010 A request for a new Recording Session MUST be
redirected to an available SRS. – REQ-023 The mechanism MUST support a means for a SIP UA
to request that a session is not recorded. – REQ-024 The mechanism MUST provide a means of indicating
to the end users of a Communication Session that the session in which they are participating is being recorded.
– REQ-030 The mechanism MUST enable the Recording Session to identify itself as a SIP session that is established for the purpose of recording.
• Does not address any Metadata requirements
SIPREC WG 3July 30, 2010
Proposal
• Extend SIP Caller/Callee Capabilities– RFC 3840– Contact header field parameters– Transported in dialog creating and modifying requests
and responses• Define 3 new feature tags
– sip.srs– sip.src– sip.recorded
• Use Caller Preferences– RFC 3841
SIPREC WG 4July 30, 2010
sip.src Feature Tag
• Indicates UA is a Session Recording Client• Identifies a SIP dialog as a Recording
Session– This feature tag is not used in Recorded
Session, but is used in the Recording Session– The Session Recording Server can tell it is
talking to an SRC using this feature tag• Meets REQ-30
SIPREC WG 5July 30, 2010
sip.srs Feature Tag
• Indicates UA is a Session Recording Server• Identifies a SIP dialog as a Recording Session• Meets REQ-30• To meet REQ-10, Accept-Contact: *;sip.srs
allows a UA to request that the INVITE be routed to an SRS. – To be completely sure, the SRC would need to
include a Require: prefs header field field in the request.
SIPREC WG 6July 30, 2010
sip.recorded Feature Tag
• Used exclusively in recorded Communication Sessions by the Session Recording Client (SRC)
• Indicates the dialog is a Communication Session that is being recorded– Used if at least one media session established with
the dialog is being recorded
• Meets REQ-24– Other indications will likely be used (media path)– Lack of this feature tag does not guarantee call is not
being recorded
SIPREC WG 7July 30, 2010
Open Issue
• Could possibly use Reject-Contact: *;sip.recorded and Require:prefs to meet REQ-23
• Alternatively, a new SIP option tag could be used, e.g. Require:nosiprecord– Depends on the interpretation of the
requirement – must the call be failed if recording happens?
– Do we need media stream granularity?• OK to record audio but not video
SIPREC WG 8July 30, 2010
Next Steps
• Interest in mechanism?• Need to wait for final requirements• How to meet other Requirements?
