Internet DRAFT - draft-ietf-siprec-metadata
draft-ietf-siprec-metadata
SIPREC R. Ravindranath
Internet-Draft Cisco Systems
Intended status: Standards Track Parthasarathi. Ravindran
Expires: October 6, 2016 Nokia Networks
Paul. Kyzivat
Huawei
April 4, 2016
Session Initiation Protocol (SIP) Recording Metadata
draft-ietf-siprec-metadata-22
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. This document describes the metadata model as
viewed by Session Recording Server(SRS) and the Recording metadata
format.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 6, 2016.
Copyright Notice
Copyright (c) 2016 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
(http://trustee.ietf.org/license-info) in effect on the date of
Ravindranath, et al. Expires October 6, 2016 [Page 1]
Internet-Draft SIP Recording Metadata April 2016
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Metadata Model . . . . . . . . . . . . . . . . . . . . . . . 4
5. Recording metadata format from SRC to SRS . . . . . . . . . . 6
5.1. XML data format . . . . . . . . . . . . . . . . . . . . . 6
5.1.1. Namespace . . . . . . . . . . . . . . . . . . . . . . 7
5.1.2. recording . . . . . . . . . . . . . . . . . . . . . . 7
6. Recording metadata classes . . . . . . . . . . . . . . . . . 7
6.1. Recording Session . . . . . . . . . . . . . . . . . . . . 7
6.1.1. Attributes . . . . . . . . . . . . . . . . . . . . . 8
6.1.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 8
6.2. Communication Session Group . . . . . . . . . . . . . . . 9
6.2.1. Attributes . . . . . . . . . . . . . . . . . . . . . 9
6.2.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 10
6.3. Communication Session . . . . . . . . . . . . . . . . . . 10
6.3.1. Attributes . . . . . . . . . . . . . . . . . . . . . 11
6.3.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 12
6.4. CSRSAssociation . . . . . . . . . . . . . . . . . . . . . 13
6.4.1. Attributes . . . . . . . . . . . . . . . . . . . . . 13
6.4.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 13
6.5. Participant . . . . . . . . . . . . . . . . . . . . . . . 14
6.5.1. Attributes . . . . . . . . . . . . . . . . . . . . . 14
6.5.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 15
6.6. ParticipantCSAssociation . . . . . . . . . . . . . . . . 15
6.6.1. Attributes . . . . . . . . . . . . . . . . . . . . . 16
6.6.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 17
6.7. Media Stream . . . . . . . . . . . . . . . . . . . . . . 17
6.7.1. Attributes . . . . . . . . . . . . . . . . . . . . . 18
6.7.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 18
6.8. ParticipantStreamAssociation . . . . . . . . . . . . . . 18
6.8.1. Attributes . . . . . . . . . . . . . . . . . . . . . 19
6.8.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 20
6.9. Syntax of date/time XML elements . . . . . . . . . . . . 20
6.10. Unique ID format . . . . . . . . . . . . . . . . . . . . 20
6.11. Metadata version Indicator . . . . . . . . . . . . . . . 21
7. Recording metadata snapshot request format . . . . . . . . . 21
8. SIP Recording Metadata Example . . . . . . . . . . . . . . . 22
8.1. Complete SIP Recording Metadata Example . . . . . . . . . 22
Ravindranath, et al. Expires October 6, 2016 [Page 2]
Internet-Draft SIP Recording Metadata April 2016
8.2. Partial Update of Recording metadata XML body . . . . . . 24
9. XML Schema definition for Recording metadata . . . . . . . . 24
10. Security Considerations . . . . . . . . . . . . . . . . . . . 28
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
11.1. SIP recording metadata Schema Registration . . . . . . . 29
12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 29
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 29
13.1. Normative References . . . . . . . . . . . . . . . . . . 29
13.2. Informative References . . . . . . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
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. This document focuses on the Recording metadata
which describes the communication session. The document describes a
metadata model as viewed by Session Recording Server(SRS) and the
Recording metadata format, the requirements for which are described
in [RFC6341] and the architecture for which is described in
[RFC7245].
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. Definitions
Metadata model: An abstract representation of metadata using a
Unified Modelling Language (UML) [UML-REF] class diagram.
Metadata classes: Each block in the model represents a class. A
class is a construct that is used as a blueprint to create
instances(called objects) of itself. The description of each class
also has representation of its attributes in a second compartment
below the class name.
Attributes: Attributes represent the elements listed in each of the
classes. The attributes of a class are listed in the second
compartment below the class name. Each instance of class conveys
values for these attributes which adds to the recording's metadata.
Ravindranath, et al. Expires October 6, 2016 [Page 3]
Internet-Draft SIP Recording Metadata April 2016
Linkages: Linkages represent the relationship between the classes in
the model. Each represents a logical connection between classes(or
objects) in class diagrams(or object diagrams). The linkages used in
the metadata model of this document are associations.
This document also refers to the terminlogy defined in [RFC6341].
4. Metadata Model
Metadata is the information that describes recorded media and the
Communication Session(CS) to which they relate. The diagram below
shows a model for metadata as viewed by a SRS.
Ravindranath, et al. Expires October 6, 2016 [Page 4]
Internet-Draft SIP Recording Metadata April 2016
+-------------------------------+ 1..*
| Recording Session (RS) |----+
+-------------------------------+ |
|1..* | 1..* |
| | |
| | 0..* |
| +-----------------+ |
+------------+ | | Communication | |
| CSRS | | | Session | |
| Association|--+ | Group | |
| | | +-----------------+ |
+------------+ | | 0..1 |
| | |
|0..* | 1..* |
+-------------------------------+ |
| Communication Session (CS) | |
| | |
+-------------------------------+ |
| 1..* |0..1 |
+-----+ | |
| | 0..* |0..* |0..*
| +-------------+ receives +----------------+ |
| | Participant |----------| Media Stream |--+
| | |0..* 0..*| |
| | | | |
| | | | |
| | | sends | |
| | |----------| |
| | |1.* 0..*| |
| +-------------+ +----------------+
| | |
| | |
| +------------------------+------------+
| |
| |
| +------------------+ +----------------------+
| |ParticipantCS | | ParticipantStream |
+-----------| Association | | Association |
| | | |
+------------------+ +----------------------+
The metadata model is a class diagram in UML. The model describes
the structure of metadata in general by showing the classes, their
attributes, and the relationships among the classes. Each block in
the model above represents a class. The linkages between the classes
Ravindranath, et al. Expires October 6, 2016 [Page 5]
Internet-Draft SIP Recording Metadata April 2016
represent the relationships which can be associations or composition.
The metadata is conveyed from SRC to SRS.
The model allows metadata describing communications sessions to be
communicated to the SRS as a series of snapshots, each representing
the state as seen by a single SRC at a particular instant in time.
Metadata changes from one snapshot to another reflect changes in what
is being recorded. For example, if a participant joins a conference,
then the SRC sends the SRS a snapshot of metadata having that
participant information (with attributes like name/AoR pair and
associate-time.)
Some of the metadata is not required to be conveyed explicitly from
the SRC to the SRS, if it can be obtained contextually by the
SRS(e.g., from SIP or SDP signalling). For example, the label
attribute within the 'stream' XML element references an SDP 'a=label'
attribute that identifies an m-line within the Recording Session(RS)
SDP. The SRS would learn the media properties from media line.
5. Recording metadata format from SRC to SRS
This section gives an overview of the Recording metadata format.
Some data from the metadata model is assumed to be made available to
the SRS through Session Description Protocol (SDP)[RFC4566], and
therefore this data is not represented in the XML document format
specified in this document. SDP attributes describe different media
formats like audio, video. The other metadata attributes, such as
participant details, are represented in a new recording specific XML
document of type 'application/rs-metadata+xml'. The SDP label
attribute [RFC4574] provides an identifier by which a metadata XML
document can refer to a specific media description in the SDP sent
from the SRC to the SRS.
The XML document format can be used to represent either the complete
metadata or a partial update to the metadata. The latter includes
only elements that have changed compared to the previously reported
metadata.
5.1. XML data format
Every recording metadata XML document sent from SRC to SRS contain
a'recording' element. The 'recording' element acts as a container
for all other elements in this XML document. A 'recording' object is
an XML document. It has the XML declaration and contain an encoding
declaration in the XML declaration, e.g., "<?xml version='1.0'
encoding='UTF-8'?>". 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.
Ravindranath, et al. Expires October 6, 2016 [Page 6]
Internet-Draft SIP Recording Metadata April 2016
Every application conforming to this specification MUST accept the
UTF-8 character encoding to ensure the minimal interoperability.
Syntax and semantic errors in an XML document should be reported to
the originator using application specific mechanisms.
5.1.1. Namespace
This document defines a new namespace URI for elements defined by
this specification is the following URN:
urn:ietf:params:xml:ns:recording:1
5.1.2. recording
The 'recording' element MUST contain an xmlns namespace attribute
with value as urn:ietf:params:xml:ns:recording:1. Exactly one
recording element MUST be present in every recording metadata XML
document.
A recording element MAY contain a <dataMode> element indicating
whether the XML document is a complete document or a partial update.
If no <dataMode> element is present then the default value is
"complete".
6. Recording metadata classes
This section describes each class of the metadata model, and the
attributes of each class. This section also describes how different
classes are linked and the XML element for each of them.
6.1. Recording Session
Ravindranath, et al. Expires October 6, 2016 [Page 7]
Internet-Draft SIP Recording Metadata April 2016
+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
| |1..* 0..*
| start-time |-------------- Media Stream
| end-time |
| |
| |
+-------------------------------+
|1..* | 1..*
| |
|0..* | 0..*
Communication Communication
Session Session Group(CS Group)
Each instance of a Recording Session(RS) class namely the RS Object
represents a SIP session created between an SRC and SRS for the
purpose of recording a Communication Session(CS).
RS object is represented in XML schema using 'recording' element.
That in turn relies on the SIP/SDP session with which the XML
document is associated to provide the attributes of the RS element.
6.1.1. Attributes
An RS class has the following attributes:
o start-time - Represents the start time of an RS object.
o end-time - Represents the end time of an RS object.
'start-time' and 'end-time' attribute values are derivable from Date
header(if present in SIP message) in RS. In cases where Date header
is not present, 'start-time' is derivable from the time at which SRS
receives the notification of SIP message to setup RS and and 'end-
time' is derivable from the time at which SRS receives disconnect on
the RS SIP dialog.
6.1.2. Linkages
Each instance of RS has:
o Zero or more instances of Communication Session Group (CS-Group).
o Zero or more instances of CS objects.
o Zero or more instances of MediaStream objects.
Ravindranath, et al. Expires October 6, 2016 [Page 8]
Internet-Draft SIP Recording Metadata April 2016
Zero instances of CS and CS-Group in a recording element is allowed
to accommodate persistent recording scenarios. A persistent RS is a
SIP dialog that is setup between SRC to SRS even before any CS is
setup. The metadata sent from SRC to SRS when the persistent RS SIP
dialog is setup may not have any CS(and the related CS-Group)
elements in the XML as there may be no session that is associated to
the RS yet. For e.g; a phone acting as SRC can setup a RS with SRS
possibly even before phone is part of a CS. Once the phone joins a
CS, the same RS would be used to convey the CS metadata.
6.2. Communication Session Group
Recording Session (RS)
| 1..*
|
| 0..*
+-------------------------------+
| Communication Session |
| Group |
+-------------------------------+
| group_id |
| associate-time |
| disassociate-time |
| |
+-------------------------------+
| 0..1
|
| 1..*
Communication Session (CS)
One instance of a Communication Session Group(CS-Group) class namely
the CS-Group object provides association or grouping of all related
CSs. For e.g, in a contact center flow a call can get transferred to
multiple agents. Each of these can trigger setup of new CS. In
cases where the SRC knows the related CSs it can group them using the
CS-Group element. CS-Group object is represented in XML schema using
'group' element.
6.2.1. Attributes
A CS-Group has the following attributes:
o group_id - This is to group different CSs that are related. SRC
(or SRS) is responsible for ensuring the uniqueness of 'group_id'
in case multiple SRC interacts with the same SRS. The mechanism
by which SRC groups the CS is outside the scope of this document.
Ravindranath, et al. Expires October 6, 2016 [Page 9]
Internet-Draft SIP Recording Metadata April 2016
o associate-time - This is the time when a grouping is formed. The
rules that determine how a grouping of different CS objects is
done by SRC is outside the scope of this document.
o disassociate-time - 'disassociate-time' for CS-Group is calculated
by SRC as the time when the grouping ends.
6.2.2. Linkages
The linkages between CS-Group class and other classes are
associations. A CS-Group is associated with RS and CS in the
following manner:
o There are one or more RS objects per CS-Group.
o Each CS-Group object has to be associated with one or more RS.
Here each RS can be setup by the potentially different SRCs.
o There are one or more CSs per CS-Group (for example, in case where
the call is transferred). A CS cannot be associated with more
than one CS-Group.
6.3. Communication Session
Recording Communication
Session Session Group(CS Group)
|1..* | 0..1
| |
|0..* | 1..*
+-------------------------------+
| Communication Session (CS) |
+-------------------------------+
| session_id |
| sipSessionID |
| reason |
| group-ref |
| start-time |
| stop-time |
+-------------------------------+
| |
| 0..* |0..1
| |
| 0..* |0..*
Participant Media Stream
Ravindranath, et al. Expires October 6, 2016 [Page 10]
Internet-Draft SIP Recording Metadata April 2016
A Communication Session(CS) class and its object in the metadata
model represents the CS and its properties as seen by SRC. CS object
is represented in XML schema using 'session' element.
6.3.1. Attributes
A CS class has the following attributes:
o session_id - This attribute is used to uniquely identify an
instance of CS object namely the session XML element with in the
metadata XML document. 'session_id' is generated using the rules
mentioned in Section 6.10.
o reason - This represents the reason why a CS was terminated. The
value for this attribute is derived from SIP Reason header
[RFC3326] of CS. There MAY be multiple instances of the 'reason'
XML element inside a 'session' element. The 'reason' XML element
has 'protocol' as an attribute, which indicates the protocol from
which the reason string is derived. The default value for
protocol attribute is "SIP". The 'reason' element can be derived
from a SIP Reason header in the CS.
o sipSessionID - This attribute carries sip Session-ID defined in
[I-D.ietf-insipid-session-id]. Each CS object can have zero or
more sipSessionID elements. More than one 'sipSessionID'
attribute may be present in a CS. For example, if three
participants A, B and C are in a conference that has a focus
acting as SRC, the metadata sent from the SRC to the SRS will
likely have three 'sipSessionID' elements that correspond to the
SIP dialogs the focus has with each of the three participants.
o group-ref - A 'group-ref' attribute MAY be present to indicate the
group(identified by 'group_id') to which the enclosing session
belongs.
o start-time - This optional attribute represents start time of CS
as seen by SRC.
o stop-time - This optional attribute represents stop time of CS as
seen by SRC.
This document does not specify attributes relating to what should
happen to a recording of a CS after it has been delivered to the SRS
(E.g., how long to retain the recording, what access controls to
apply.) The SRS is assumed to behave in accordance with its local
policy. The ability for the SRC to influence this policy is outside
the scope of this document. However if there are implementations
Ravindranath, et al. Expires October 6, 2016 [Page 11]
Internet-Draft SIP Recording Metadata April 2016
where SRC desires to specify its own policy preferences, this could
be sent as extension data attached to the CS.
6.3.2. Linkages
A CS is linked to CS-Group, Participant, Media Stream and RS classes
using the association relationship. Association between CS and
participant allows:
o CS to have zero or more participants
o Participant is associated with zero or more CSs. This includes
participants who are not directly part of any CS. An example of
such a case is participants in a premixed media stream. The SRC
may have knowledge of such participants, yet not have any
signaling relationship with them. This might arise if one
participant in CS is a conference focus. To summarize, even if
the SRC does not have direct signalling relationships with all
participants in a CS, it should nevertheless create a participant
object for each participant that it knows about.
o The model also allows participants in CS that are not participants
in the media. An example is the identity of a Third Party Call
Control(3pcc) that has initiated a CS to two or more participants
of the CS. Another example is the identity of a conference focus.
Of course a focus is probably in the media, but since it may only
be there as a mixer, it may not report itself as a participant in
any of the media streams.
Association between CS and Media Stream allows:
o A CS to have zero or more streams
o A stream can be associated with at most one CS. A stream in a
persistent RS is not required to be associated with any CS before
the CS is created and hence the zero association is allowed.
Association between CS and RS allows:
o Each instance of RS has zero or more instances of CS objects.
o Each CS has to be associated with one more RS. Each RS can be
potentially setup by different SRCs.
Ravindranath, et al. Expires October 6, 2016 [Page 12]
Internet-Draft SIP Recording Metadata April 2016
6.4. CSRSAssociation
1..* 0..*
Recording Communication
Session ----------+---------- Session
|
|
|
+-----------------------+
| CSRSAssociation |
| |
+-----------------------+
| associate-time |
| disassociate-time |
| session_id |
+-----------------------+
The CSRSAssociation class describes the association of a CS to an RS
for a period of time. A single CS may be associated with different
RSs (perhaps by different SRCs) and may be associated and dissociated
several times.
The CSRSAssociation is represented in XML using
'sessionrecordingassoc' XML element.
6.4.1. Attributes
CSRSAssociation class has the following attributes:
o associate-time - associate-time is calculated by SRC as the time
it sees a CS associated to a RS
o disassociate-time- disassociate-time is calculated by SRC as the
time it see a CS disassociate from a RS.
o session_id - Each instance of this class MUST have 'session_id'
attribute that identifies the the CS to which this association
belongs to.
6.4.2. Linkages
CSRSAssociation class is linked to CS and RS classes.
Ravindranath, et al. Expires October 6, 2016 [Page 13]
Internet-Draft SIP Recording Metadata April 2016
6.5. Participant
Communication Session (CS)
| 0..*
|
| 0..*
+-------------------------------+
| Participant |
+-------------------------------+
| nameID |
| participant_id |
| |
+-------------------------------+
| 0..* 1..*|
receives| |sends
| 0..* 0..*|
Media Stream
A participant class and its objects has information about a device
that is part of a CS and/or contributes/consumes media stream(s)
belonging to a CS.
Participant object is represented in XML schema using 'participant'
element.
6.5.1. Attributes
A participant class has two attributes:
o nameID - This attribute is a list of Name, Address-of-Record (AoR)
defined in Section 6 of [RFC3261] tuples. An AoR can be one of
SIP/SIPS/TEL URI, FQDN or IP address. For example, the AoR may be
drawn from the From header field or P-Asserted-Identity header
[RFC3325] field. SRC's local policy is used to decide on where to
draw the AoR from. Name represents participant name(SIP display
name) or dialed number (DN) (when known). Multiple tuples are
allowed for cases where a participant has more than one AoR. For
example, a P-Asserted-identity header can have both SIP and TEL
URIs.
o participant_id - This attribute is used to identify the
'participant' XML element with in the XML document. It is
generated using the rules mentioned in Section 6.10. This
attribute MUST be used for all references to a participant within
Ravindranath, et al. Expires October 6, 2016 [Page 14]
Internet-Draft SIP Recording Metadata April 2016
a CS-Group, and MAY be used to reference the same participant more
globally.
This document does not specify other attributes relating to
participant e.g. participant role, participant type. An SRC which
has information of these attributes can indicate the same as part of
extension data to participant from SRC to SRS.
6.5.2. Linkages
The participant class is linked to MediaStream (MS) and CS class
using association relationship. The association between participant
and MS allows:
o participant to receive zero or more media streams.
o participant to send zero or more media streams. (Same participant
provides multiple streams e.g. audio and video)
o media stream to be received by zero or more participants. Its
possible, though perhaps unlikely, that a stream is generated but
sent only to the SRC and SRS, not to any participant. E.g. In
conferencing where all participants are on hold and the SRC is
collocated with the focus. Also a media stream may be received by
multiple participants (e.g. Whisper calls, side conversations).
o media stream to be sent by one or more participants (pre-mixed
streams).
Example of a case where a participant receives zero or more streams -
a supervisor may have side conversation with agent, while agent
converses with customer.
6.6. ParticipantCSAssociation
Ravindranath, et al. Expires October 6, 2016 [Page 15]
Internet-Draft SIP Recording Metadata April 2016
1..* 0..*
Communication
Session ----------+---------- Participant
|
|
|
+-------------------------+
| ParticipantCSAssociation|
| |
| |
+-------------------------+
| associate-time |
| disassociate-time |
| param |
| participant_id |
| session_id |
+-------------------------+
The ParticipantCSAssociation class describes the association of a
participant to an CS for a period of time. A participant may be
associated and dissociated from a CS several times. (For example,
connecting to a conference, then disconnecting, then connecting
again.)
ParticipantCSAssociation object is represented in XML schema using
'participantsessionassoc' element.
6.6.1. Attributes
ParticipantCS association class has the following attributes:
o associate-time - associate-time is calculated by SRC as the time
it sees a participant associated to a CS.
o disassociate-time- disassociate-time is calculated by the SRC as
the time it sees a participant disassociate from a CS. It is
possible that a given participant can have multiple associate/
disassociate times within given communication session.
o param - An optional attribute describing the capabilities of a
participant in a CS, as defined in [RFC3840]. For example, in a
CS(which can be a conference), you can have participants who are
playing the role of "focus". These participants does not
contribute to media in the CS, however they switch the media
received from one participant to every other participant in the
CS. Indicating the capability of participant (here "focus") would
be useful for recorder to learn about these kind of participants.
Ravindranath, et al. Expires October 6, 2016 [Page 16]
Internet-Draft SIP Recording Metadata April 2016
The capablities are represented using 'param' XML element in the
metadata. The 'param' XML element encoding defined in [RFC4235]
is used to represent the capabilties attributes in metadata. Each
participant may have zero or more capabilities. A participant may
use different capabilities depending on the role it plays at a
particular instance. For example, if a participant moves across
different CSs (e.g., due to transfer) or is simultaneously present
in different CSs with different roles.
o participant_id - This attribute identifies the participant to
which this association belongs to.
o session_id - This attribute identifies the session to which this
association belongs to.
6.6.2. Linkages
The participantCSAssociation class is linked to participant and CS
classes.
6.7. Media Stream
Participant
| 0..* 1..*|
receives| |sends
| 0..* 0..*|
+-------------------------+
| Media Stream |
Communication 0..1 0..* +-------------------------+
Session ------------| |
| label |
| content-type |
| stream_id |
| session_id |
+-------------------------+
0..*|
|
|
1..*|
Recording Session
A MS class (and its objects) has the properties of media as seen by
SRC and sent to SRS. Different snapshots of a MS objects may be sent
whenever there is a change in media (e.g. direction change like
pause/resume and/or codec change and/or participant change.).
Ravindranath, et al. Expires October 6, 2016 [Page 17]
Internet-Draft SIP Recording Metadata April 2016
MS object is represented in XML schema using 'stream' element.
6.7.1. Attributes
A MS class has the the following attributes:
o label - The label attribute within the 'stream' XML element
references an SDP 'a=label' attribute that identifies an m-line
within the RS SDP. That m-line carries the media stream from the
SRC to the SRS.
o content-type - The content of an MS element will be described in
terms of value from the [RFC4796] registry. If the SRC wishes to
convey the Content-type to the SRS, it does so by including an
'a=content' attribute with the m-line in the RS SDP.
o stream_id - Each stream element has unique 'stream_id' attribute
which helps to uniquely identify stream. This identifier is
generated using the rules mentioned in Section 6.10.
o session_id - This attribute associates the stream with a specific
session element.
The metadata model can include media streams that are not being
delivered to the SRS. For example, an SRC offers audio, video
towards SRS which in response accepts only audio. The metadata
snapshots sent from SRC to SRS can continue to indicate the changes
to video stream as well.
6.7.2. Linkages
A MS class is linked to participant and CS classes using the
association relationship. The details of association with the
participant are described in the participant class section. The
details of association with CS is mentioned in the CS section.
6.8. ParticipantStreamAssociation
Ravindranath, et al. Expires October 6, 2016 [Page 18]
Internet-Draft SIP Recording Metadata April 2016
+-------------------------+
| ParticipantStream |
| Association |
+-------------------------+ +----------Participant
| association-time | | 0..*| 1..*|
| disassociaton-time |---+ recv| |sends
| send | | 0..*| 0..*|
| recv | | | |
| participant_id | | | |
+-------------------------+ | | |
+----------Media Stream
A ParticipantStreamAssociation class describes the association of a
Participant to a MS for a period of time, as a sender or as a
receiver, or both.
This class is represented in XML using 'participantstreamassoc'
element.
6.8.1. Attributes
A ParticipantStreamAssociation class has the following attributes:
o associate-time: This attribute indicates the time a participant
started contributing to a MS.
o disassociate-time: This attribute indicates the time a participant
stopped contributing to a MS.
o send: This attribute indicates whether a participant is
contributing to a stream or not. This attribute has a value which
points to stream represented by its unique_id. The presence of
this attribute indicates that a participant is contributing to a
stream. If due to changes in CS if a participant stops
contributing to a stream, a snapshot MUST be sent from SRC to SRS
with no send element for that stream.
o recv: This attribute indicates whether a participant is receiving
a media stream or not. This attribute has a value which points to
a stream represented by its unique_id. The presence of this
attribute indicates that a participant is receiving a stream. If
due to changes in CS(like hold) the participants stops receiving a
stream, a snapshot MUST be sent from SRC to SRS with no recv
element for that stream.
Ravindranath, et al. Expires October 6, 2016 [Page 19]
Internet-Draft SIP Recording Metadata April 2016
o participant_id - This attributes points to the participant to
which a stream element is associated with.
'participantstreamassoc' XML element is used to represent a
participant association with a stream. The 'send' and 'recv' XML
elements MUST be used to indicate whether a participant is
contributing to a stream or receiving a stream. There MAY be
multiple instances of the 'send' and 'recv' XML elements inside a
'particpantstreamassoc' element. If a metadata snapshot is sent with
a 'participantstreamassoc' element that does not have any 'send' and
'recv' elements, it means that participant is neither contributing to
any streams nor receiving any streams.
6.8.2. Linkages
The ParticipantStreamAssociation class is linked to participant and
MS classes.
6.9. Syntax of date/time XML elements
XML elements 'associate-time', 'disassociate-time', 'start-time' and
'stop-time' contain strings representing the date and time. The
value of these elements 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 MUST be included in all
tuples unless the exact time of the status change cannot be
determined.
6.10. Unique ID format
A Unique id is generated in two steps:
o The UUID is created using procedures mentioned in Sections 4.3,
4.4 or 4.5 of [RFC4122]. The algorithm MUST ensure that it does
not use anything potentially personally identifying to generate
the UUIDs. If implementations are using a Name-Based UUID as
defined in Section 4.3 of [RFC4122], a name space ID generated
using Section 4.2 or 4.5 of [RFC4122] might be a good choice.
o The UUID is encoded using base64 as defined in [RFC4648]
The above mentioned unique-id mechanism SHOULD be used for each
metadata element. Multiple SRC's can refer to the same element/UUID
(how each SRC learns the UUID here is out of scope of this document).
If two SRCs use the same UUID, they MUST retain the UUID/element
mapping. If the SRS detects that a UUID is mapped to more than one
Ravindranath, et al. Expires October 6, 2016 [Page 20]
Internet-Draft SIP Recording Metadata April 2016
element at any point of time it MUST treat this as a error. For
example, the SRS may choose to reject or ignore the portions of
metadata where it detects same UUID is mapped to a different elements
other than the expected element (the SRS learns the mapped UUID when
it sees a element for the first time in a metadata instance).
6.11. Metadata version Indicator
Metadata version is defined to help SRC and SRS to know the version
of metadata XML schema used. SRCs and SRSs that support this
specification MUST use version 1 in the
namespace(urn:ietf:params:xml:ns:recording:1) in all the XML
documents. Implementations may not interoperate if the version
implemented by the sender is not known by the receiver. No
negotiation of versions is provided. There is no significance to the
version number although documents which update or obsolete this
document (possibly including drafts of such documents) should include
a higher version number if the metadata XML schema changes.
7. Recording metadata snapshot request format
SRS can explicitly request metadata snapshot from SRC. To request a
metadata snapshot the SRS MUST send a SIP request message with a XML
document having the namespace urn:ietf:params:xml:ns:recording:1.
The XML document has the following elements.
o A <requestsnapshot> XML element MUST be present as the top level
element in the XML document.
o A <requestreason> XML element that indicates the reason for
requesting snapshot as a string MAY be present as a child XML
element of <requestsnapshot>.
The example below shows a metadata snapshot request from SRS.
<?xml version="1.0" encoding="UTF-8"?>
<requestsnapshot xmlns='urn:ietf:params:xml:ns:recording:1'>
<requestreason xml:lang="it">SRS internal error</requestreason>
</requestsnapshot>
Example metadata snapshot request from SRS to SRC
Ravindranath, et al. Expires October 6, 2016 [Page 21]
Internet-Draft SIP Recording Metadata April 2016
8. SIP Recording Metadata Example
8.1. Complete SIP Recording Metadata Example
The following example provides all the tuples involved in Recording
Metadata XML body.
<?xml version="1.0" encoding="UTF-8"?>
<recording xmlns='urn:ietf:params:xml:ns:recording:1'>
<datamode>complete</datamode>
<group group_id="7+OTCyoxTmqmqyA/1weDAg==">
<associate-time>2010-12-16T23:41:07Z</associate-time>
<!-- Standardized extension -->
<call-center xmlns='urn:ietf:params:xml:ns:callcenter'>
<supervisor>sip:alice@atlanta.com</supervisor>
</call-center>
<mydata xmlns='http://example.com/my'>
<structure>FOO!</structure>
<whatever>bar</whatever>
</mydata>
</group>
<session session_id="hVpd7YQgRW2nD22h7q60JQ==">
<sipSessionID>ab30317f1a784dc48ff824d0d3715d86;
remote=47755a9de7794ba387653f2099600ef2</sipSessionID>
<group-ref>7+OTCyoxTmqmqyA/1weDAg==</group-ref>
<!-- Standardized extension -->
<mydata xmlns='http://example.com/my'>
<structure>FOO!</structure>
<whatever>bar</whatever>
</mydata>
</session>
<participant participant_id="srfBElmCRp2QB23b7Mpk0w==">
<nameID aor="sip:bob@biloxi.com">
<name xml:lang="it">Bob B</name>
</nameID>
<!-- Standardized extension -->
<mydata xmlns='http://example.com/my'>
<structure>FOO!</structure>
<whatever>bar</whatever>
</mydata>
</participant>
<participant participant_id="zSfPoSvdSDCmU3A3TRDxAw==">
<nameID aor="sip:Paul@biloxy.com">
<name xml:lang="it">Paul</name>
</nameID>
<!-- Standardized extension -->
<mydata xmlns='http://example.com/my'>
Ravindranath, et al. Expires October 6, 2016 [Page 22]
Internet-Draft SIP Recording Metadata April 2016
<structure>FOO!</structure>
<whatever>bar</whatever>
</mydata>
</participant>
<stream stream_id="UAAMm5GRQKSCMVvLyl4rFw=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<label>96</label>
</stream>
<stream stream_id="i1Pz3to5hGk8fuXl+PbwCw=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<label>97</label>
</stream>
<stream stream_id="8zc6e0lYTlWIINA6GR+3ag=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<label>98</label>
</stream>
<stream stream_id="EiXGlc+4TruqqoDaNE76ag=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<label>99</label>
</stream>
<sessionrecordingassoc session_id="hVpd7YQgRW2nD22h7q60JQ==">
<associate-time>2010-12-16T23:41:07Z</associate-time>
</sessionrecordingassoc>
<participantsessionassoc
participant_id="srfBElmCRp2QB23b7Mpk0w=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<associate-time>2010-12-16T23:41:07Z</associate-time>
</participantsessionassoc>
<participantsessionassoc
participant_id="zSfPoSvdSDCmU3A3TRDxAw=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<associate-time>2010-12-16T23:41:07Z</associate-time>
</participantsessionassoc>
<participantstreamassoc
participant_id="srfBElmCRp2QB23b7Mpk0w==">
<send>i1Pz3to5hGk8fuXl+PbwCw==</send>
<send>UAAMm5GRQKSCMVvLyl4rFw==</send>
<recv>8zc6e0lYTlWIINA6GR+3ag==</recv>
<recv>EiXGlc+4TruqqoDaNE76ag==</recv>
</participantstreamassoc>
<participantstreamassoc
participant_id="zSfPoSvdSDCmU3A3TRDxAw==">
<send>8zc6e0lYTlWIINA6GR+3ag==</send>
<send>EiXGlc+4TruqqoDaNE76ag==</send>
<recv>UAAMm5GRQKSCMVvLyl4rFw==</recv>
<recv>i1Pz3to5hGk8fuXl+PbwCw==</recv>
</participantstreamassoc>
</recording>
Ravindranath, et al. Expires October 6, 2016 [Page 23]
Internet-Draft SIP Recording Metadata April 2016
Example metadata snapshot from SRC to SRS
8.2. Partial Update of Recording metadata XML body
The following example provides partial update in Recording metadata
XML body for the above example. The example has a snapshot that
carries the disassociate-time for a participant from a session.
<?xml version="1.0" encoding="UTF-8"?>
<recording xmlns='urn:ietf:params:xml:ns:recording:1'>
<datamode>partial</datamode>
<participant
participant_id="srfBElmCRp2QB23b7Mpk0w==">
<nameID aor="sip:bob@biloxi.com">
<name xml:lang="it">Bob R</name>
</nameID>
</participant>
<participantsessionassoc
participant_id="srfBElmCRp2QB23b7Mpk0w=="
session_id="hVpd7YQgRW2nD22h7q60JQ==">
<disassociate-time>2010-12-16T23:41:07Z</disassociate-time>
</participantsessionassoc>
</recording>
Partial update of SIP Recording Example XML body
9. XML Schema definition for Recording metadata
This section defines XML schema for Recording metadata document
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema targetNamespace="urn:ietf:params:xml:ns:recording:1"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:tns="urn:ietf:params:xml:ns:recording:1"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<!-- This import brings in the XML language attribute xml:lang-->
<xs:import namespace="http://www.w3.org/XML/1998/namespace"
schemaLocation="https://www.w3.org/2001/xml.xsd"/>
<xs:element name="recording" type="tns:recording"/>
<xs:complexType name="recording">
<xs:sequence>
<xs:element name="datamode" type="tns:dataMode"
minOccurs="0"/>
<xs:element name="group" type="tns:group"
Ravindranath, et al. Expires October 6, 2016 [Page 24]
Internet-Draft SIP Recording Metadata April 2016
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="session" type="tns:session"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="participant" type="tns:participant"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="stream" type="tns:stream"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="sessionrecordingassoc"
type="tns:sessionrecordingassoc"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="participantsessionassoc"
type="tns:participantsessionassoc"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="participantstreamassoc"
type="tns:participantstreamassoc"
minOccurs="0" maxOccurs="unbounded"/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="group">
<xs:sequence>
<xs:element name="associate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:element name="disassociate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="group_id" type="xs:base64Binary"
use="required"/>
</xs:complexType>
<xs:complexType name="session">
<xs:sequence>
<xs:element name="sipSessionID" type="xs:string" minOccurs="0"
maxOccurs="unbounded"/>
<xs:element name="reason" type="tns:reason" minOccurs="0"
maxOccurs="unbounded"/>
<xs:element name="group-ref" type="xs:base64Binary"
minOccurs="0" maxOccurs="1"/>
<xs:element name="start-time" type="xs:dateTime"
minOccurs="0" maxOccurs="1"/>
<xs:element name="stop-time" type="xs:dateTime"
minOccurs="0" maxOccurs="1"/>
Ravindranath, et al. Expires October 6, 2016 [Page 25]
Internet-Draft SIP Recording Metadata April 2016
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="session_id" type="xs:base64Binary"
use="required"/>
</xs:complexType>
<xs:complexType name="sessionrecordingassoc">
<xs:sequence>
<xs:element name="associate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:element name="disassociate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="session_id" type="xs:base64Binary"
use="required"/>
</xs:complexType>
<xs:complexType name="participant">
<xs:sequence>
<xs:element name="nameID" type="tns:nameID"
maxOccurs='unbounded'/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="participant_id" type="xs:base64Binary"
use="required"/>
</xs:complexType>
<xs:complexType name="participantsessionassoc">
<xs:sequence>
<xs:element name="associate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:element name="disassociate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:element name="param" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="pname" type="xs:string" use="required"/>
<xs:attribute name="pval" type="xs:string" use="required"/>
</xs:complexType>
</xs:element>
<xs:any namespace='##other'
minOccurs='0'
Ravindranath, et al. Expires October 6, 2016 [Page 26]
Internet-Draft SIP Recording Metadata April 2016
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="participant_id" type="xs:base64Binary"
use="required"/>
<xs:attribute name="session_id" type="xs:base64Binary"
use="required"/>
</xs:complexType>
<xs:complexType name="participantstreamassoc">
<xs:sequence>
<xs:element name="send" type="xs:base64Binary"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="recv" type="xs:base64Binary"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="associate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:element name="disassociate-time" type="xs:dateTime"
minOccurs="0"/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="participant_id" type="xs:base64Binary"
use="required"/>
</xs:complexType>
<xs:complexType name="stream">
<xs:sequence>
<xs:element name="label" type="xs:string"
minOccurs="0" maxOccurs="1"/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
<xs:attribute name="stream_id" type="xs:base64Binary"
use="required"/>
<xs:attribute name="session_id" type="xs:base64Binary"/>
</xs:complexType>
<xs:simpleType name="dataMode">
<xs:restriction base="xs:string">
<xs:enumeration value="complete"/>
<xs:enumeration value="partial"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="nameID">
<xs:sequence>
<xs:element name="name" type ="tns:name" minOccurs="0"
Ravindranath, et al. Expires October 6, 2016 [Page 27]
Internet-Draft SIP Recording Metadata April 2016
maxOccurs="1"/>
</xs:sequence>
<xs:attribute name="aor" type="xs:anyURI" use="required"/>
</xs:complexType>
<xs:complexType name="name">
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute ref="xml:lang" use="optional"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:complexType name="reason">
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute type="xs:short" name="cause" use="required"/>
<xs:attribute type="xs:string" name="protocol" default="SIP"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:element name="requestsnapshot" type="tns:requestsnapshot"/>
<xs:complexType name="requestsnapshot">
<xs:sequence>
<xs:element name="requestreason" type="tns:name" minOccurs="0"/>
<xs:any namespace='##other'
minOccurs='0'
maxOccurs='unbounded'
processContents='lax'/>
</xs:sequence>
</xs:complexType>
</xs:schema>
10. Security Considerations
This document describes an extensive set of metadata that may be
recorded by the SRS. Most of the metadata could be considered
private data. The procedures mentioned in security consideration
section of [I-D.ietf-siprec-protocol] MUST be followed by SRC and SRS
for mutual authentication and to protect the content of the metadata
in the RS.
An SRC MAY, by policy, choose to limit the parts of the metadata sent
to the SRS for recording. And the policy of the SRS might not
require recording all the metadata it receives. For the sake of data
minimization, the SRS MUST NOT record additional metadata that is not
explicitly required by local policy. Metadata in storage needs to be
provided with a level of security that is comparable to that of the
recording session.
Ravindranath, et al. Expires October 6, 2016 [Page 28]
Internet-Draft SIP Recording Metadata April 2016
11. IANA Considerations
This specification registers a new XML namespace, and a new XML
schema.
11.1. SIP recording metadata Schema Registration
URI: urn:ietf:params:xml:ns:recording:1
Registrant Contact: IETF SIPREC working group, Ram Mohan
R(rmohanr@cisco.com)
XML: the XML schema to be registered is contained in Section 8.
Its first line is <?xml version="1.0" encoding="UTF-8"?> and its last
line is </xs:schema>
12. Acknowledgement
Thanks to John Elwell, Henry Lum, Leon Portman, De Villers, Andrew
Hutton, Deepanshu Gautam,Charles Eckel, Muthu Arul Mozhi, Michael
Benenson, Hadriel Kaplan, Brian Rosen, Scott Orton, Ofir Roth, Mary
Barnes, Ken Rehor, Gonzalo Salgueiro, Yaron Pdut, Alissa Cooper,
Stephen Farrell and Ben Campbell for their valuable comments and
inputs.
Thanks to Joe Hildebrand, Peter Saint-Andre, Matt Miller for helping
in writing the XML schema and Martin Thomson for validating the XML
schema and providing comments on the same.
13. References
13.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141,
May 1997, <http://www.rfc-editor.org/info/rfc2141>.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002,
<http://www.rfc-editor.org/info/rfc3261>.
Ravindranath, et al. Expires October 6, 2016 [Page 29]
Internet-Draft SIP Recording Metadata April 2016
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<http://www.rfc-editor.org/info/rfc3339>.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, DOI 10.17487/RFC4566,
July 2006, <http://www.rfc-editor.org/info/rfc4566>.
[RFC4574] Levin, O. and G. Camarillo, "The Session Description
Protocol (SDP) Label Attribute", RFC 4574,
DOI 10.17487/RFC4574, August 2006,
<http://www.rfc-editor.org/info/rfc4574>.
[RFC4796] Hautakorpi, J. and G. Camarillo, "The Session Description
Protocol (SDP) Content Attribute", RFC 4796,
DOI 10.17487/RFC4796, February 2007,
<http://www.rfc-editor.org/info/rfc4796>.
[RFC3840] Rosenberg, J., Schulzrinne, H., and P. Kyzivat,
"Indicating User Agent Capabilities in the Session
Initiation Protocol (SIP)", RFC 3840,
DOI 10.17487/RFC3840, August 2004,
<http://www.rfc-editor.org/info/rfc3840>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005,
<http://www.rfc-editor.org/info/rfc4122>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<http://www.rfc-editor.org/info/rfc4648>.
[I-D.ietf-siprec-protocol]
Portman, L., Lum, H., Eckel, C., Johnston, A., and A.
Hutton, "Session Recording Protocol", draft-ietf-siprec-
protocol-18 (work in progress), September 2015.
13.2. Informative References
[RFC6341] Rehor, K., Ed., Portman, L., Ed., Hutton, A., and R. Jain,
"Use Cases and Requirements for SIP-Based Media Recording
(SIPREC)", RFC 6341, DOI 10.17487/RFC6341, August 2011,
<http://www.rfc-editor.org/info/rfc6341>.
Ravindranath, et al. Expires October 6, 2016 [Page 30]
Internet-Draft SIP Recording Metadata April 2016
[I-D.ietf-insipid-session-id]
Jones, P., Salgueiro, G., Pearce, C., and P. Giralt, "End-
to-End Session Identification in IP-Based Multimedia
Communication Networks", draft-ietf-insipid-session-id-18
(work in progress), February 2016.
[RFC7245] Hutton, A., Ed., Portman, L., Ed., Jain, R., and K. Rehor,
"An Architecture for Media Recording Using the Session
Initiation Protocol", RFC 7245, DOI 10.17487/RFC7245, May
2014, <http://www.rfc-editor.org/info/rfc7245>.
[RFC2648] Moats, R., "A URN Namespace for IETF Documents", RFC 2648,
DOI 10.17487/RFC2648, August 1999,
<http://www.rfc-editor.org/info/rfc2648>.
[RFC3326] Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason
Header Field for the Session Initiation Protocol (SIP)",
RFC 3326, DOI 10.17487/RFC3326, December 2002,
<http://www.rfc-editor.org/info/rfc3326>.
[RFC3325] Jennings, C., Peterson, J., and M. Watson, "Private
Extensions to the Session Initiation Protocol (SIP) for
Asserted Identity within Trusted Networks", RFC 3325,
DOI 10.17487/RFC3325, November 2002,
<http://www.rfc-editor.org/info/rfc3325>.
[RFC4235] Rosenberg, J., Schulzrinne, H., and R. Mahy, Ed., "An
INVITE-Initiated Dialog Event Package for the Session
Initiation Protocol (SIP)", RFC 4235,
DOI 10.17487/RFC4235, November 2005,
<http://www.rfc-editor.org/info/rfc4235>.
[UML-REF] OMG, "Unified Modeling Language (UML)", 2011,
<http://www.omg.org/spec/UML/2.4/>.
Authors' Addresses
Ram Mohan Ravindranath
Cisco Systems
Cessna Business Park
Bangalore, Karnataka
India
Email: rmohanr@cisco.com
Ravindranath, et al. Expires October 6, 2016 [Page 31]
Internet-Draft SIP Recording Metadata April 2016
Parthasarathi Ravindran
Nokia Networks
Bangalore, Karnataka
India
Email: partha@parthasarathi.co.in
Paul Kyzivat
Huawei
Hudson, MA
USA
Email: pkyzivat@alum.mit.edu
Ravindranath, et al. Expires October 6, 2016 [Page 32]
