siprec Ram Mohan. Ravindranath
Internet-Draft Parthasarathi. Ravindran
Intended status: Standards Track Paul. Kyzivat
Expires: July 25, 2011 Cisco Systems, Inc.
January 21, 2011
Session Initiation Protocol (SIP) Recording Metadata Format
draft-ram-siprec-metadata-format-00
Abstract
Session recording is a critical requirement in many communications
environments such as call centers and financial trading. In some of
these environments, all calls must be recorded for regulatory,
compliance, and consumer protection reasons. Recording of a session
is typically performed by sending a copy of a media stream to a
recording device. The requirements for which are described in
[I-D.ietf-siprec-req], the architecture for which is described in
[I-D.ietf-siprec-architecture], and the metadata model viewed by
Session Recording Server is described in [I-D.ram-siprec-metadata].
This document focuses on the Recording metadata format which
describes the communication session.
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on July 25, 2011.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Recording Metadata Format . . . . . . . . . . . . . . . . . . 3
4. SIP Recording Metadata document format . . . . . . . . . . . . 4
4.1. Contents . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2. XML data format . . . . . . . . . . . . . . . . . . . . . 4
4.2.1. Namespace . . . . . . . . . . . . . . . . . . . . . . 4
4.2.2. recording . . . . . . . . . . . . . . . . . . . . . . 4
4.2.3. group . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2.4. sessions . . . . . . . . . . . . . . . . . . . . . . . 5
4.2.5. session . . . . . . . . . . . . . . . . . . . . . . . 5
4.2.6. participants . . . . . . . . . . . . . . . . . . . . . 5
4.2.7. participant . . . . . . . . . . . . . . . . . . . . . 5
4.2.8. streams . . . . . . . . . . . . . . . . . . . . . . . 6
4.2.9. stream . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2.10. appdata . . . . . . . . . . . . . . . . . . . . . . . 6
4.2.11. timestamp . . . . . . . . . . . . . . . . . . . . . . 6
5. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. XML Schema definition for Recording metadata . . . . . . . . . 8
7. XML element usage in SIP methods . . . . . . . . . . . . . . . 11
8. Usecases with SIP message . . . . . . . . . . . . . . . . . . 12
9. Security Considerations . . . . . . . . . . . . . . . . . . . 12
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
10.1. SIP recording metadata Schema Registration . . . . . . . . 12
11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 12
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
12.1. Normative References . . . . . . . . . . . . . . . . . . . 12
12.2. Informative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
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1. Introduction
Session recording is a critical requirement in many communications
environments such as call centers and financial trading. In some of
these environments, all calls must be recorded for regulatory,
compliance, and consumer protection reasons. Recording of a session
is typically performed by sending a copy of a media stream to a
recording device. The requirements for which are described in
[I-D.ietf-siprec-req], the architecture for which is described in
[I-D.ietf-siprec-architecture], and the metadata model viewed by
Session Recording Server is described in [I-D.ram-siprec-metadata].
This document focuses on the Recording metadata format which
describes the communication session. The delivery mechanism for
passing metadata is outside the scope of this document.
The Session Recording Client (SRC) SHALL initiate the Recording
Session. It should be noted that the Recording Session is a
completely independent from the Communication Session that is being
recorded at both the SIP dialog level and at the session level.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. This
document only uses these key words when referencing normative
statements in existing RFCs.
3. Recording Metadata Format
Recording Metadata is the data that describes the communication
session. Metadata has to be conveyed from SRC to SRS, further the
metadata MAY be conveyed in the Recording Session dialog and SRS may
send metadata to convey Key information to SRC.
The media related details of metadata SHALL be passed across using
session description protocol (SDP) [RFC4566]. SDP attributes
describes about different media formats like audio, video. The other
metadata attributes like participant details MUST be passed across in
new Recording specific XML document namely application/recording.
The linkage between application/recording XML schema and metadata SDP
is done using the SDP label attribute (a=label:xxx) referenced in
[RFC4574].
Metadata is passed across in Recording Session(RS) incrementally
whenever there is a change in CS.
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4. SIP Recording Metadata document format
4.1. Contents
Recording Metadata document is an XML document which will be embedded
as a message body. The document contains
o Entity parameter in recording-metadata to specify the recording
client URI
o Participant Tuple provides the information about the individual
participants involved in the recording
o Stream Tuple indicates the SDP media lines associated with the CS
and participants
4.2. XML data format
REC object is a XML document. It MUST have the XML declaration and
it SHOULD contain an encoding declaration in the XML declaration,
e.g., "". If the charset
parameter of the MIME content type declaration is present and it is
different from the encoding declaration, the charset parameter takes
precedence.
Every application conformant to this specification MUST accept the
UTF-8 character encoding to ensure the minimal interoperability.
4.2.1. Namespace
The namespace URI for elements defined by this specification is a
Uniform Resource Namespace (URN) [RFC2141], using the namespace
identifier 'ietf' defined by [RFC2648] and extended by [RFC3688].
The URN is as follows: urn:ietf:params:xml:ns:siprec
4.2.2. recording
recording element MUST contain an xmlns namespace attribute with
value as urn:ietf:params:xml:ns:siprec. recording object shall be
uniquely identified by RS transaction id with RS dialog id.
There are other elements associated in the recording-metadata
element. The element information is as follows:
o recording requestor attribute indicates whether SRC or SRS
initiates the particular session. The default value is SRC.
o recording type shows whether the type of recording belongs to
selective or persistent. The default value is selective.
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o Open Issue: whether Partial update of Metadata XML document is
required ?
4.2.3. group
Each communication session group (CSG) has one group tuple.
All group element have one sessions element. Each communication
session is defined by one session tuple.
Each group element has unique id attribute which helps to uniquely
identify CSG. Whether id element has to be generated by SRC or SRS
is an open issue.
Each group MAY have initiator entity attribute which contains SIP/
SIPS URI to identify the device which acts as Session Recording
Client (SRC). The entity attribute SIP/SIPS URI FQDN or IP address
represents the device and may not have user part.
4.2.4. sessions
All sessions element have one or more session element. This is a
container element to list of communication session in a given
recording session.
4.2.5. session
Each communication session(CS) has one session tuple.
All session element have zero or one participants element.
Each session element has unique id attribute which helps to uniquely
identify CS. Whether id element has to be generated by SRC or SRS is
an open issue.
4.2.6. participants
All Participants element have one or more participant element. This
is a container element to list the participant in the session.
4.2.7. participant
Each communication session user is defined by one participant tuple.
The streams tuple in each participant is associating SDP m-lines with
the participant.
Participant MUST have AOR element which contains SIP/SIPS URI to
identify the participant. AOR element is SIP/SIPS URI FQDN or IP
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address which represents the user.
4.2.8. streams
All Streams element have one or more stream element. This is a
container element to list the stream in the session.
4.2.9. stream
This element indicates the SDP m-line properties like label
attributes, media mode. Label attribute is used to link m-line SDP
body. Label attribute MUST be unique within the given recording
session. The media mode helps in understanding whether the media is
mixed or not.
4.2.10. appdata
Appdata element SHALL include any other XML namespace. Multiple
namespace MAY exists under appdata. Appdata element exist in each
level like recording, session, participant, stream to provide to
provide appdata specific to each element.
4.2.11. timestamp
Timestamp element contains a string indicating the date and time of
the status change of this tuple. The value of this element MUST
follow the IMPP datetime format [RFC3339]. Timestamps that contain
'T' or 'Z' MUST use the capitalized forms.
As a security measure, the timestamp element SHOULD be included in
all tuples unless the exact time of the status change cannot be
determined.
5. Example
The example provides all the tuples involved in Recording Metadata
XML body.
SRCselective42
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FOO!barFOO!barsip:romeo@example.comb13d7bb0-2a9f-48a8-85be-43557269aab8sip:romeo@example.comRomeo MontagueFOO!barsip:juliet@example.netJuliet CapuletFOO!bar2010-12-16T23:41:07Z
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2010-12-16T23:41:07ZFOO!barFOO!bar
SIP Recording Example XML body
6. XML Schema definition for Recording metadata
This section defines XML schema for Recording metadata document
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7. XML element usage in SIP methods
Table 1 provides the XML element usage in SIP methods. Most of the
columns are defined in [RFC3261], the column 'PRA' is for the PRACK
method [RFC3262],'UPD' is for the UPDATE method [RFC3311], 'SUB' is
for the SUBSCRIBE method [RFC3265], 'NOT' is for the NOTIFY method
[RFC3265] and 'INF' is for the INFO method [RFC3261] .
+----------------+-----+---+---+---+---+---+---+---+---+---+---+---+
|XML Element |where|ACK|BYE|CAN|INV|OPT|REG|PRA|UPD|SUB|NOT|INF|
+----------------+-----+---+---+---+---+---+---+---+---+---+---+---+
|recording | R | o | o | - | o | - | - | o | o | - | o | o |
| | | | | | | | | | | | | |
|recording | 2xx | - | o | - | o | - | - | - | - | - | - | - |
| | | | | | | | | | | | | |
|group | R | o | o | - | o | - | - | o | o | - | o | o |
| | | | | | | | | | | | | |
|group | 2xx | - | o | - | o | - | - | - | - | - | - | - |
| | | | | | | | | | | | | |
|session | R | o | o | - | o | - | - | o | o | - | o | o |
| | | | | | | | | | | | | |
|session | 2xx | - | o | - | o | - | - | - | - | - | - | - |
| | | | | | | | | | | | | |
|participant | R | o | o | - | o | - | - | o | o | - | o | o |
| | | | | | | | | | | | | |
|participant | 2xx | - | o | - | o | - | - | - | - | - | - | - |
| | | | | | | | | | | | | |
|stream | R | o | - | - | o | - | - | o | o | - | - | - |
| | | | | | | | | | | | | |
|stream | 2xx | - | - | - | o | - | - | - | o | - | - | - |
| | | | | | | | | | | | | |
+------------- --+-----+---+---+---+---+---+---+---+---+---+---+---+
Table 1: XML element usage in SIP Methods
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8. Usecases with SIP message
TBD
9. Security Considerations
TBD
10. IANA Considerations
This specification registers a new XML namespace, and a new XML
schema.
10.1. SIP recording metadata Schema Registration
URI: urn:ietf:params:xml:ns:recording
Registrant Contact: IETF SIPREC working group, Ram mohan
R(rmohanr@cisco.com)
XML: the XML schema to be registered is contained in Section 6.
Its first line is and its last
line is
11. Acknowledgement
We wish to thank Joe Hildebrand (Cisco) for the valuable XML related
guidance. Thanks to Michael Benenson(Cisco) for his inputs.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997.
[RFC2648] Moats, R., "A URN Namespace for IETF Documents", RFC 2648,
August 1999.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
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Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
[RFC3262] Rosenberg, J. and H. Schulzrinne, "Reliability of
Provisional Responses in Session Initiation Protocol
(SIP)", RFC 3262, June 2002.
[RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific
Event Notification", RFC 3265, June 2002.
[RFC3311] Rosenberg, J., "The Session Initiation Protocol (SIP)
UPDATE Method", RFC 3311, October 2002.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC3339] Klyne, G., Ed. and C. Newman, "Date and Time on the
Internet: Timestamps", RFC 3339, July 2002.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006.
[RFC4574] Levin, O. and G. Camarillo, "The Session Description
Protocol (SDP) Label Attribute", RFC 4574, August 2006.
12.2. Informative References
[I-D.ietf-siprec-req]
Rehor, K., Portman, L., Hutton, A., and R. Jain,
"Requirements for SIP-based Media Recording (SIPREC)",
draft-ietf-siprec-req-06 (work in progress),
December 2010.
[I-D.ietf-siprec-architecture]
Hutton, A., Portman, L., Jain, R., and K. Rehor, "An
Architecture for Media Recording using the Session
Initiation Protocol", draft-ietf-siprec-architecture-01
(work in progress), October 2010.
[I-D.ram-siprec-metadata]
R, R., R, P., and P. Kyzivat, "Session Initiation Protocol
(SIP) Recording Metadata", draft-ram-siprec-metadata-03
(work in progress), January 2011.
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Authors' Addresses
Ram Mohan R
Cisco Systems, Inc.
Cessna Business Park,
Kadabeesanahalli Village, Varthur Hobli,
Sarjapur-Marathahalli Outer Ring Road
Bangalore, Karnataka 560103
India
Email: rmohanr@cisco.com
R Parthasarathi
Cisco Systems, Inc.
Cessna Business Park,
Kadabeesanahalli Village, Varthur Hobli,
Sarjapur-Marathahalli Outer Ring Road
Bangalore, Karnataka 560103
India
Email: partr@cisco.com
P. Kyzivat
Cisco Systems, Inc.
1414 Massachusetts Avenue
Boxborough, MA 01719
USA
Email: pkyzivat@cisco.com
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