SIPREC R. Ravindranath
Internet-Draft Cisco Systems
Intended status: Standards Track Parthasarathi. Ravindran
Expires: August 10, 2016 Nokia Networks
Paul. Kyzivat
Huawei
February 7, 2016
Session Initiation Protocol (SIP) Recording Metadata
draft-ietf-siprec-metadata-20
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 August 10, 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
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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
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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 . . . . . . . . . . . . . . . 8
6.2.1. Attributes . . . . . . . . . . . . . . . . . . . . . 9
6.2.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 9
6.3. Communication Session . . . . . . . . . . . . . . . . . . 10
6.3.1. Attributes . . . . . . . . . . . . . . . . . . . . . 10
6.3.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 11
6.4. CSRSAssociation . . . . . . . . . . . . . . . . . . . . . 12
6.4.1. Attributes . . . . . . . . . . . . . . . . . . . . . 13
6.4.2. Linkages . . . . . . . . . . . . . . . . . . . . . . 13
6.5. Participant . . . . . . . . . . . . . . . . . . . . . . . 13
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 . . . . . . . . . . . . . . . 20
7. Recording metadata snapshot request format . . . . . . . . . 21
8. SIP Recording Metadata Example . . . . . . . . . . . . . . . 21
8.1. Complete SIP Recording Metadata Example . . . . . . . . . 21
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8.2. Partial Update of Recording metadata XML body . . . . . . 23
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 . . . . . . . . . . . . . . . . . 31
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) 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.
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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.
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+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
|1..* | 1..*
| |
| | 0..*
| +-----------------+
+------------+ | | Communication |
| CSRS | | | Session (CS) |
| Association|--+ | Group |
| | | +-----------------+
+------------+ | | 0..1
| |
|0..* | 1..*
+-------------------------------+
| Communication Session (CS) |
| |
+-------------------------------+
| 1..* |0..1
+-----+ |
| | 0..* |0..*
| +-------------+ receives +----------------+
| | Participant |----------| Media Streams |
| | |0..* 0..*| |
| | | | |
| | | | |
| | | sends | |
| | |----------| |
| | |1.* 0..*| |
| +-------------+ +----------------+
| | |
| | |
| +------------------------+------------+
| |
| |
| +------------------+ +----------------------+
| |ParticipantCS | | ParticipantStream |
+-----------| Association | | Association |
| | | |
+------------------+ +----------------------+
The metadata model is a class diagram in Unified Modelling
Language(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 represent the
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relationships which can be associations or composition. The metadata
is conveyed from SRC to SRS.
The model allows the capture of a snapshot of a recording's metadata
at a given instant in time. Metadata changes to 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).
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 MUST
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 MUST have the XML
declaration and it SHOULD 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.
Every application conforming to this specification MUST accept the
UTF-8 character encoding to ensure the minimal interoperability.
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Syntax and semantic errors in an XML document should be reported to
the originator using application specific mechanisms.
5.1.1. 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: 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. 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
+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
| |
| start-time |
| end-time |
| |
| |
+-------------------------------+
|1..* | 1..*
| |
|0..* | 0..*
Communication Communication
Session Session Group(CS Group)
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Each instance of a Recording Session(RS) class namely the Recording
Session 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
A RS class has the following attributes:
o start-time - Represents the start time of a RS object.
o end-time - Represents the end time of a 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 (CSG).
o Zero or more instances of CS objects.
CSs and CSGs are optional to accommodate persistent recording, where
there may sometimes be none.
6.2. Communication Session Group
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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 Communication Session Group object provides association or
linking of Communication Sessions.
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 SIPREC.
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 SIPREC.
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.
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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).
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
A Communication Session(CS) class and its object in the metadata
model represents a CS and its properties needed 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.
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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 may be
present in a CS for conference flows. 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
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
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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.
6.4. CSRSAssociation
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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.
6.5. Participant
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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/AoR tuples. An AoR can
be one of SIP/SIPS/TEL URI, FQDN or IP address. The AoR MAY be
drawn from From header or P-Asserted-Identity header or Remote-
Party-ID header. 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 [RFC3325] 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 a CSG, 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
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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
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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.
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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 |
+-------------------------+
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.).
MS object is represented in XML schema using <stream> element.
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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
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+-------------------------+
| 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.
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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 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 SHOULD 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 [RFC4122]
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 SIPREC)
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
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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
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>
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</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'>
<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=="
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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>
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.
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<?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"
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"
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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"/>
<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">
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<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'
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">
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<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"
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>
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</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. For this reason, it is RECOMMENDED that a SRC use a
strong means for authentication and metadata information protection
and that it apply comprehensive authorization rules when using the
metadata format defined in this document.
It is RECOMMENDED that a SRC authenticate the SRS using the normal
SIP authentication mechanisms, such as Digest as defined in
Section 22 of [RFC3261]. The mechanism used for conveying the
metadata information MUST ensure integrity and confidentially of the
information. In order to achieve these, an end-to-end SIP encryption
mechanism, such as S/MIME described in [RFC3261], SHOULD be used.
If a strong end-to-end security means (such as above) is not
available, it is RECOMMENDED that a SRC use mutual hop-by-hop
Transport Layer Security (TLS) authentication and encryption
mechanisms described in "SIPS URI Scheme" and "Interdomain Requests"
of [RFC3261].
Some implementations may have the SRC choose parts of metadata that
can be sent to the SRS. In other cases, SRCs may send metadata that
is not appropriate for the SRS to record. Which metadata is actually
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recorded by the SRS must be carefully considered to balance privacy
concerns with usability. Implementations MUST control what metadata
is recorded, and MUST NOT save metadata sent by the SRC that does not
conform to the recording policy of the SRS. Metadata in storage
needs to be provided with a level of security that is comparable to
that of the recording session.
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 and Alissa Cooper
for their valuable comments and inputs.
Thanks to Joe Hildebrand, Peter Saint-Andre, Matt Miller for helping
in writing the XML schema and Martin Thompson 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>.
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[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>.
[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-insipid-session-id]
Jones, P., Salgueiro, G., and C. Pearce, "End-to-End
Session Identification in IP-Based Multimedia
Communication Networks", draft-ietf-insipid-session-id-16
(work in progress), October 2015.
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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>.
[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>.
Authors' Addresses
Ram Mohan Ravindranath
Cisco Systems
Cessna Business Park
Bangalore, Karnataka
India
Email: rmohanr@cisco.com
Ravindranath, et al. Expires August 10, 2016 [Page 31]
Internet-Draft SIP Recording Metadata February 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 August 10, 2016 [Page 32]