SIPREC Ram Mohan. Ravindranath
Internet-Draft Parthasarathi. Ravindran
Intended status: Standards Track Paul. Kyzivat
Expires: December 22, 2011 Cisco Systems, Inc.
June 20, 2011
Session Initiation Protocol (SIP) Recording Metadata
draft-ietf-siprec-metadata-01
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).
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 December 22, 2011.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
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
Ravindranath, et al. Expires December 22, 2011 [Page 1]
Internet-Draft SIP Recording Metadata June 2011
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. Metadata Model . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Recording Metadata elements . . . . . . . . . . . . . . . . . 5
4.1. Recording Session . . . . . . . . . . . . . . . . . . . . 5
4.1.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 5
4.1.2. Associations . . . . . . . . . . . . . . . . . . . . . 6
4.2. Communication Session Group . . . . . . . . . . . . . . . 6
4.2.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 6
4.2.2. Associations . . . . . . . . . . . . . . . . . . . . . 7
4.3. Communication Session . . . . . . . . . . . . . . . . . . 7
4.3.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 8
4.3.2. Associations . . . . . . . . . . . . . . . . . . . . . 8
4.4. Participant . . . . . . . . . . . . . . . . . . . . . . . 9
4.4.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 9
4.4.2. Associations . . . . . . . . . . . . . . . . . . . . . 10
4.5. Media Stream . . . . . . . . . . . . . . . . . . . . . . . 10
4.5.1. Attributes . . . . . . . . . . . . . . . . . . . . . . 11
4.5.2. Associations . . . . . . . . . . . . . . . . . . . . . 11
4.6. Extension Data . . . . . . . . . . . . . . . . . . . . . . 11
5. Metadata Model Object Instances . . . . . . . . . . . . . . . 11
5.1. Use case 1: Basic Call . . . . . . . . . . . . . . . . . . 11
5.2. Use case 2: Basic Call with hold/resume . . . . . . . . . 12
5.3. Use case 3: Basic call with Transfer . . . . . . . . . . . 14
5.4. Conference Use Cases . . . . . . . . . . . . . . . . . . . 15
5.4.1. Case 1: . . . . . . . . . . . . . . . . . . . . . . . 16
5.4.2. Case 2: . . . . . . . . . . . . . . . . . . . . . . . 18
5.4.3. Case 3: . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.4. Case 4: . . . . . . . . . . . . . . . . . . . . . . . 21
6. Security Considerations . . . . . . . . . . . . . . . . . . . 22
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
8. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 22
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.1. Normative References . . . . . . . . . . . . . . . . . . . 22
9.2. Informative References . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
Ravindranath, et al. Expires December 22, 2011 [Page 2]
Internet-Draft SIP Recording Metadata June 2011
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, the
requirements for which are described in [I-D.ietf-siprec-req] and the
architecture for which is described in
[I-D.ietf-siprec-architecture].
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. Metadata Model
Metadata is the information that describes recorded media and the CS
to which they relate. Below diagram shows a model for Metadata as
viewed by Session Recording Server (SRS).
Ravindranath, et al. Expires December 22, 2011 [Page 3]
Internet-Draft SIP Recording Metadata June 2011
+-------------------------------+ 1
| Recording Session (RS) |---------------+
+-------------------------------+ |
|1..* | 1..* |
| | |
| | 0..* |
| +-----------------+ |
| | Communication | |
| | Session (CS) | 1 |
| | Group |--------------|
| +-----------------+ |
| | 0..1 |
| | |
|0..* | 1..* |
+-------------------------------+ |
| Communication Session (CS) | 1 |
| |---------------|
+-------------------------------+ | +------------+
| 1..* |1..* | | |
| | | 0..* |Extension |
| 2..* |0..* |-------| Data |
+-------------+ receives +----------------+ | | |
| Participant |----------| Media Streams | | +------------+
| |0..* 0..*| | |
| | | | |
| | | | |
| | sends | | |
| |----------| | |
| |1.* 0..*| | |
+-------------+ +----------------+ |
| | |
|1 |1 |
| | |
+----------------------------------------+
The mechanism MUST provide a means to convey every attribute
mentioned in the metadata model. Session Recording Client (SRC) MAY
initiate the Recording Session. Here, Recording Session is a
completely independent from the Communication Session that is being
recorded at both the SIP dialog level and at the session level. The
metadata MUST be conveyed from SRC to SRS. The metadata MAY be
conveyed within the Recording Session Dialog.
Note that the metadata model captures changes that occur over the
duration of the recording session. For example, if the call is
Ravindranath, et al. Expires December 22, 2011 [Page 4]
Internet-Draft SIP Recording Metadata June 2011
transferred from one participant to another, then the SRC SHALL
convey a change of participant and the properties of the new media
stream to the SRS.
Some of the data in the model may not be conveyed explicitly from the
SRC to the SRS, if it can be obtained contextually by the SRS. For
instance, the timing of RS block changes(like Start / Stop time) may
not be explicitly conveyed from the SRC to the SRS (The Date header
in RS dialog SIP message MAY provide the timing, but it is optional).
In such cases the time a change occurred may be assumed to be the
same as the time when notification of the change is received by the
SRS.
4. Recording Metadata elements
This section describes each element of the metadata model, and the
attributes of each element. This section also describes how
different elements are associated.
4.1. Recording Session
+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
| | +-----------------+
| Start/End Time | 1 0..* | |
| |------------|Extension Data |
| | | |
| | +-----------------+
+-------------------------------+
|1..* | 1..*
| |
|0..* | 0..*
Communication Communication
Session Session Group(CS Group)
A Recording Session element represents a SIP session created between
an SRC and SRS for the purpose of recording a Communication Session.
A SIP RS dialog SHALL be mapped to this element and hence there is no
need for this element to be reflected in metadata XML.
4.1.1. Attributes
A Recording Session element MAY have attributes like:
Ravindranath, et al. Expires December 22, 2011 [Page 5]
Internet-Draft SIP Recording Metadata June 2011
o Start/End Time - Start and End time value SHALL be derived from
Date header(if present in SIP message) in RS. In cases where Date
header is not present, Start/End time SHALL be the time at which
SRS receive the SIP message to setup RS / disconnect RS.
4.1.2. Associations
One instance of Recording Session SHALL have:
o Zero or more instances of Communication Session Group. CSG may be
zero because it is optional metadata block. Also the allowance of
zero instances is to accommodate persistent recording, where there
may be none.
o Zero or more instances of Communication Session blocks.
o Each CS Group MUST be associated with one or more Recording
Sessions [Here each RS can be setup by the potentially different
SRCs.]
4.2. Communication Session Group
Recording Session (RS)
| 1..*
|
| 0..*
+-------------------------------+
| Communication Session |
| Group |
+-------------------------------+
| Unique-ID | +----------------+
| | 1 0..* | |
| |-----------|Extension Data |
| | | |
+-------------------------------+ +----------------+
| 0..1
|
| 1..*
Communication Session (CS)
A Communication Session Group provides association or linking of
Communication Sessions.
4.2.1. Attributes
A CS Group MUST have a Unique-ID attribute. This Unique-ID is to
group different CSs that are related. SRC (or MAY be SRS) MUST
ensure the uniqueness of Unique-ID in case multiple SRC interacts
Ravindranath, et al. Expires December 22, 2011 [Page 6]
Internet-Draft SIP Recording Metadata June 2011
with the same SRS. The mechanism by which SRC groups the CS is
outside the scope of SIPREC.
4.2.2. Associations
A communication Session Group SHALL be associated with RS and CS in
the following manner:
o There can be one or more Recording Session elements per
Communication Session Group.
o Each Communication Session Group MUST be associated with one or
more RS [Here each RS can be setup by the potentially different
SRCs]
o There MAY be one or more Communication Sessions per CS Group [e.g.
Consult Transfer]
o Each CS MAY be associated to zero or one CS-Group
4.3. Communication Session
Recording Communication
Session Session Group(CS Group)
|1..* | 0..1
| |
|0..* | 1..*
+-------------------------------+ +-----------------+
| Communication Session (CS) | 1 0..* | |
| |---------------|Extension Data |
+-------------------------------+ | |
| CS Identifier | +-----------------+
| Termination Reason |
| Start Time |
| End Time |
+-------------------------------+
| |
| 1..* |1..*
| |
| 2..* |0..*
Participant Media Stream
A Communication Session block/element in the metadata model
represents Communication Session and its properties needed as seen by
SRC.
Ravindranath, et al. Expires December 22, 2011 [Page 7]
Internet-Draft SIP Recording Metadata June 2011
4.3.1. Attributes
A communication Session block SHALL have the following attributes:
o Termination Reason - This represents the reason why a CS was
terminated. The communication session MAY contain a Call
Termination Reason. This MAY be derived from SIP Reason header of
CS.
o CS Identifier - This attribute is used to uniquely identify a CS.
o Start Time - This optional attribute represents CS start time
o End Time - This optional attribute represents CS end time
Attributes like Retention (represent the value/duration for which
Media streams of the CS needs to be retained), Force Deletion, Access
Information e.t.c that are primarily related to policy will not be
passed in metadata from SRC to SRS. However if there are
implementations where SRC has enough information, this could be sent
as Extension Data attached to CS
4.3.2. Associations
A Communication Session SHALL be associated to CS-Group, Participant,
Media Stream and Recording Session blocks. Cardinalities between CS
and Participant allows:
o CS to have atleast two or more participants
o Participant SHALL be associated with one or more CS's. This may
even 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 conf focus. Another use case is if one
UA in CS works in 3pcc mode to acquire an MoH media stream, this
might be reflected as unique source for media stream without
having a reported signaling relationship to it. In all these
cases if SRC can learn enough information about the Participant,
they SHALL be associated with CS.
o The model also allows participants in CS that are not participants
in the media. An example is the identity of a 3pcc controller
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.
Cardinalities between CS and Media Stream allows:
Ravindranath, et al. Expires December 22, 2011 [Page 8]
Internet-Draft SIP Recording Metadata June 2011
o A CS to have zero or more Streams
o A stream can be associated with 1 or more CS. An example is
multicast MoH stream which might be associated with many CSs.
Also if we were to consider a B2BUA to have a separate CS on each
"side" then they might share a stream.(Though more likely this
would be treated as a single CS.)
Cardinalities between CS and RS allows:
o One instance of RS SHALL have Zero or more instances of
Communication Session blocks.
o Each CS SHALL be associated with one more RS [ Here each RS can be
potentially setup by different SRCs]
4.4. Participant
Communication Session (CS)
| 1..*
|
| 2..*
+-------------------------------+
| Participant |
| |
+-------------------------------+
| AoR list | +-----------------+
| Name | 1 0..* | |
| Participant Type |------------|Extension Data |
| | | |
+-------------------------------+ +-----------------+
| 0..* 1..*|
receives| |sends
| 0..* 0..*|
Media Stream
A Participant block has information about a device that is part of a
CS and/or contributes/consumes media stream(s) belonging to a CS.
4.4.1. Attributes
Participant has attributes like:
o AoR list - Has list of AoRs. An AoR MAY be SIP/SIPS/TEL URI.
There MAY be cases where a participant can have more than one AoR
[ e.g. P-Asserted-ID which can have both SIP and TEL URIs]
Ravindranath, et al. Expires December 22, 2011 [Page 9]
Internet-Draft SIP Recording Metadata June 2011
o Name - This attribute represents Participant name(SIP display
name) or DN number ( in case it is known)
Other attributes [ like Participant Role, Participant type ] MAY be
carried as part of extension data to Participant from SRC to SRS.
4.4.2. Associations
Cardinalities between participant and Media Stream allows:
o Participant to receives 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 may receive Zero or more
streams - a Supervisor may have side conversation with Agent, while
Agent converses with customer.
4.5. Media Stream
Participant
| 0..* 1..*|
receives| |sends
| 0..* 0..*|
+-------------------------+
| Media Stream |
| |
Communication 1..* 0..* +-------------------------+
Session ------------| Start Time | +----------+
| End Time |1 0..* | |
| Media Stream Reference |--------|Extension |
| | | Data |
+-------------------------+ +----------+
A Media Stream block SHALL have properties of media as seen by SRC
and sent to SRS. Different instances of Media Stream block would be
created whenever there is a change in media (e.g. dir change like
pause/resume and/or codec change and/or participant change.).
Ravindranath, et al. Expires December 22, 2011 [Page 10]
Internet-Draft SIP Recording Metadata June 2011
4.5.1. Attributes
A Media Stream block SHALL have the following attributes:
o Start Time - Represents Media Start time at SRC.
o End Time - Represents Media End time at SRC. This is an optional
attribute and MAY be included after a stream ends
o Media Stream Reference - In implementations this can reference to
m-line
The metadata model should include media streams that are not being
delivered to the SRS. Examples include cases where SRC offered
certain media types but SRS chooses to accept only a subset of them
OR an SRC may not even offer a certain media type due it its
restrictions to record
4.5.2. Associations
A Media Stream SHALL be associated with Participant and CS. The
details of association with the Participant are described in the
Participant block section. The details of association with CS is
mentioned in the CS section.
4.6. Extension Data
A recording metadata object contains additional data not specified as
part of siprec. This is intended to accommodate future standards
track extensions, as well as vendor and user specific extensions.
The mechanism MUST provide a means of unambiguously distinguishing
such extension data.
5. Metadata Model Object Instances
This section describes the metadata model object instances for
different use cases of SIPREC. For the sake of simplicity as the
media streams sent by each of the participants is received by every
other participant in these use cases, it is NOT shown in the object
instance diagrams below. Also for the sake of ease not all
attributes of each block are shown in these instance diagrams.
5.1. Use case 1: Basic Call
Basic call between two Participants A and B. In this use case each
participant sends one Media Stream. For the sake of simplicity
"receives" lines are not shown in this instance diagram. Media
Streams sent by each participant is received all other participants
of that CS.
Ravindranath, et al. Expires December 22, 2011 [Page 11]
Internet-Draft SIP Recording Metadata June 2011
+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
|
|
|
+----------------+
| Communication |
| Session (CS) |
+----------------+-----------------------+
| Start Time | |
+----------------+ |
| |
|-------------------+ |
| | |
+---------------+ +---------------+ |
| ParticipantA | | ParticipantB | |
| | | | |
+---------------+ +---------------+ |
| | |
sends | | sends |
| | |
+---------------+ +---------------+ |
|Media Stream A1| |Media Stream B1| |
+---------------+ +---------------+ |
|MediaStream Ref| |MediaStream Ref| |
|Start Time | |Start Time | |
+---------------+ +---------------+ |
| | |
+-----------------------------------+
5.2. Use case 2: Basic Call with hold/resume
Basic call between two Participants A and B and with Participant A or
B doing a Hold/Resume. In this use case each participant sends one
Media Stream. After Hold/Resume the properties of Media MAY change.
For the sake of simplicity "receives" lines are not shown in this
instance diagram. Media Streams sent by each participant is received
all other participants of that CS.
+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
| |
| |
| |
Ravindranath, et al. Expires December 22, 2011 [Page 12]
Internet-Draft SIP Recording Metadata June 2011
| +-------------------------------+
| | Communication Session (CS) |
| +-----------| Group(CSG) |
| | +-------------------------------+
| | | Unique-id1 |
| | +-------------------------------+
| |
| |
| |
+----------------+
| Communication |
+-| Session (CS) |----------------------------------------------+
| +----------------+ |
| | | |
| +----------------+ |
| | |
| |-------------------+ |
| | | |
| +---------------+ +---------------+ |
| | ParticipantA | | ParticipantB |-----------+ |
| | |--+ | | | |
| +---------------+ | +---------------+ |sends(After |
| | | | | | | Resume) |
| | | | | | +--------------+ |
| sends | | +--+ | sends | |MediaStream B3| |
| | -----+ | | +-----+ +--------------+ |
| +---------------+ | | +---------------+ | |MediaStreamRef|-|
| |Media Stream A1| | | |Media Stream B1| | | Start Time | |
| +---------------+ | | +---------------+ | | | |
+-|MediaStreamref | | | |MediaStreamRef | | +--------------+ |
|Start Time | | | |Start Time |-|-------------------|
+---------------+ | | +---------------+ | |
| | | |
+------------+ |sends |sends (hold) |
| sends |(Resume) | |
| (hold) +-------+ +-------+ |
| | | |
+---------------+ +---------------+ +--------------+ |
|Media Stream A2| |Media Stream A3| |MediaStream B2| |
+---------------+ +---------------+ | | |
|MediaStreamref | |MediaStreamRef | +--------------+ |
|End Time | |Start Time | |Codec Params | |
+---------------+ +---------------+ |end Time | |
| | | | |
| | +--------------+ |
| | | |
+------------------------------------------------------+
Ravindranath, et al. Expires December 22, 2011 [Page 13]
Internet-Draft SIP Recording Metadata June 2011
5.3. Use case 3: Basic call with Transfer
Basic call between two Participants A and B and with Participant A
transfer(consult transfer) to Participant C. In this use case each
participant sends one Media Stream. After transfer the properties of
Participant A Media MAY change. For the sake of simplicity
"receives" lines are not shown in this instance diagram. Media
Streams sent by each participant is received all other participants
of that CS.
+-------------------------------+
| Recording Session (RS) |-------+
+-------------------------------+ |
| |
| |
| |
+-------------------------------+ |
| Communication Session (CS) | |
| Group(CSG) | |
+-------------------------------+ |
| Unique-id1 | |
+-------------------------------+ |
| |
|----------------------------+
|
|-----------------+
| |
+----------------+ +----------------+
| Communication | | Communication |
| Session (CS)1 | | Session (CS)2 |
+----------------+ +----------------+-----------+
| | | | |
+----------------+ +----------------+ |
| |
|-------------------+ |
| | | |
+---------------+ | +---------------+ |
| ParticipantA | | | ParticipantB | |
| | | | | |
+---------------+ | +---------------+ |
| | | |
sends | | | sends |
| | | |
+---------------+ | +---------------+ |
|Media Stream A1| | |Media Stream B1| |
+---------------+ | +---------------+ |
| | | | | |
Ravindranath, et al. Expires December 22, 2011 [Page 14]
Internet-Draft SIP Recording Metadata June 2011
| | | | Media Stream | |
| Media Stream |---+---| Ref | |
| Ref | | | |
+---------------+ +---------------+ |
|
|
+----------------------------|
| |
+--------------------------------+ |
| | |
+---------------+ +---------------+ |
| Participant A | | Participant C | |
| (same) | | | |
+---------------+ +---------------+ |
| | |
| sends (After transfer) | sends |
+----------------+ +----------------+|
| Media Stream A2| | Media Stream C1||
+----------------+ +----------------+|
| Media StreamRef| | Media StreamRef||
| | | ||
| | | ||
+----------------+ +----------------+|
| | |
| | |
| | |
+-------------------------------------------+
5.4. Conference Use Cases
Depending on who act as SRC and the information that an SRC has there
can be several ways to model conference use cases. This section has
instance diagrams for the following cases:
o A CS where one of the participant (which is also SRC) is a user in
a conference
o A CS where one of the participant is focus ( which is also SRC)
o A CS where one of the participant is user and the SRC is a
different entity like B2BUA
o A CS where one of the participant is focus and the SRC is a
different entity like B2BUA
NOTE: There MAY be other ways to model the same use cases depending
on what information the SRC has.
Ravindranath, et al. Expires December 22, 2011 [Page 15]
Internet-Draft SIP Recording Metadata June 2011
5.4.1. Case 1:
This is the usecase where there is a CS with one of the participant
(who is also SRC) as a user in a conference. For the sake of
simplicity the receive lines for each of the participant is not
shown.
+---------------------------------------------------+
| Communication Session |
| +-------------+ +--------------+ |
| | | | | |
| |Participant B| | Participant A| |
| | (User in |--------------| | |
| | conf/SRC) | | | |
| +-------------+ +--------------+ |
| | | | | |
+---------------------------------------------------+
| | | |
| | | |
D E F G (Participants of Conference)
Instance Diagram:
+-------------------------------+
| Recording Session (RS) |--+
+-------------------------------+ |
| |
| |
| |
+-------------------------------+ |
| Communication Session (CS) | |
| Group(CSG) | |
+-------------------------------+ |
| Unique-id1 | |
+-------------------------------+ |
| |
|-----------------------+
|
+----------------+
| Communication |
| Session (CS) |--+----------------+-----+
+----------------+ | | |
| | | | |
+----------------+ | | |
| | | |
| | | |
Ravindranath, et al. Expires December 22, 2011 [Page 16]
Internet-Draft SIP Recording Metadata June 2011
| | | |
+---------------+ | | |
| ParticipantA | | | |
| | | | |
+---------------+ | | |
| | | |
sends | | | |
| | | |
+---------------+ | | |
|Media Stream A1| | | |
+---------------+ | | |
|MediaStream Ref|-----|----------------+ |
| | | | |
+---------------+ | | |
| | |
| | |
+-------------+ | |
| | |
| | |
+----------------+ | |
| Participant B | | |
| (in conf) | | |
+----------------+ | |
| | |
sends | | |
| | |
+----------------+ | |
| Media Stream B1|---------------------+ |
+----------------+ sends |
| MediaStream Ref| |
| | +-----------------+
+----------------+ |
| |
|sends |
| |
+-----------------+-------------+------------+
| | | |
| | | |
+------------+ +------------+ +------------+ +-------------+
|participantD| |ParticipantE| |ParticipantF| |Participant G|
+------------+ +------------+ +------------+ +-------------+
In this example we have two participants A and B who are part of a
Communication Session(CS). One of the participants B is part of a
conference and also acts as SRC.There can be two cases here. B can
be a participant of the conference or B can be a focus. In this
Ravindranath, et al. Expires December 22, 2011 [Page 17]
Internet-Draft SIP Recording Metadata June 2011
instance diagram Participant B is a user in a conference. The SRC
(Participant B) MAY subscribe to conference event package to get the
details of other particiants. Participant B(SRC) SHALL send the same
through the metadata to SRS. In this instance diagram the Media
Stream(mixed stream) sent from Participant B SHALL have media streams
contributed by conference participants (D,E,F and G). For the sake
of simplicity the "receives" line is not shown here. In this example
the media stream sent by each participant(A or B) of CS is received
by all other participant(A or B).
5.4.2. Case 2:
This is the usecase where there is a CS where one of the participant
is focus ( which is also SRC).
+---------------------------------------------------+
| Communication Session |
| +--------------+ +--------------+ |
| | |--------------| | |
| |Participant C | | Participant A| |
| | (Focus in |------+ | | |
| | conf and SRC)|---+ | +--------------+ |
| +--------------+ | | |
| | | +---------+ |
| | | | |
| +--------------+ | +---------------+ |
| | Participant B| +---+ | Participant D | |
| | | | | | |
| +--------------+ | +---------------+ |
| | |
| +--------------+ |
| |Participant E | |
| | | |
| +--------------+ |
| |
+---------------------------------------------------+
Instance Diagram:
+-------------------------------+
| Recording Session (RS) |
+-------------------------------+
|-------------------------+
| |
| |
+-------------------------------+ |
Ravindranath, et al. Expires December 22, 2011 [Page 18]
Internet-Draft SIP Recording Metadata June 2011
| Communication Session (CS) | |
| Group(CSG) | |
+-------------------------------+ |
| Unique-id1 | |
+-------------------------------+ |
| |
|-------------------------+
|
+----------------+
| Communication |
| Session (CS) |----------------------+
+----------------+ |
| | |
+----------------+ |
| |
|-------------------+ |
| | | |
+---------------+ | +---------------+ |
| ParticipantA | | | ParticipantB | |
| | | | | |
+---------------+ | +---------------+ |
| | | |
sends | | | sends |
| | | |
+---------------+ | +---------------+ |
|Media Stream A1| | |Media Stream B1| |
+---------------+ | +---------------+ |
|MediaStream Ref| | |MediaStream Ref| |
| |---+---| | |
+---------------+ +---------------+ |
|
+----------------------------------+
| | | |
| | | |
+---------------+ | +---------------+ |
| ParticipantD | | | ParticipantE | |
| | | | | |
+---------------+ | +---------------+ |
| | | |
sends | | | sends |
| | | |
+---------------+ | +---------------+ |
|Media Stream D1| | |Media Stream E1| |
+---------------+ | +---------------+ |
|MediaStream Ref| | |MediaStream Ref| |
| |---+---| | |
+---------------+ +---------------+ |
|
Ravindranath, et al. Expires December 22, 2011 [Page 19]
Internet-Draft SIP Recording Metadata June 2011
|
+----------+
+-----------------|
| |
| |
+----------------+ |
| Participant C | |
| (focus +src) | |
+----------------+ |
| |
Sends | +-------+
| |
"sends" OR | |
contributed +----------------+
by | Media Stream C1|
Participants+----------------+ "receives" by participants A,B,D,E
A,B,D,E | MediaStream Ref|------------------------------------
------------| Codec Params |
+----------------+
In this example we have two participants A and B who are part of a
Communication Session(CS). One of the participants (C) is focus of a
conference and also acts as SRC. The SRC (Participant C) being the
Focus of the conference SHALL have access to the details of other
particiants. SRC (Participant C) SHALL send the same through the
metadata to SRS. In this instance diagram the Media Stream(mixed
stream) sent by C SHALL have media streams contributed by conference
participants (A, B, D and E). Participants A, B,D and E SHALL send
Media Streams A1, B1, D1 and E1 respectively. The media stream sent
by Participant C(Focus) shall be received by all other participants
of CS. For the sake of simplicity the "receives" line is not shown
linked to all other participants.
NOTE: SRC ( Participant C) MAY send mixed stream or seperate streams
to SRS
5.4.3. Case 3:
A CS where one of the participant is user and the SRC is a different
entity like B2BUA. In this case the SRC MAY not know that one of the
user is part of conference. Hence the instance diagram will not have
information about the conference participants.
Ravindranath, et al. Expires December 22, 2011 [Page 20]
Internet-Draft SIP Recording Metadata June 2011
+---------------------------------------------------+
| Communication Session |
| +-------------+ +------+ +--------------+ |
| | | | (SRC)| | | |
| |Participant B|--|B2BUA |----| Participant A| |
| | (User in | +------+ | | |
| | conf) | | | |
| +-------------+ +--------------+ |
| | | | | |
+---------------------------------------------------+
| | | |
| | | |
D E F G (Participants of Conference)
5.4.4. Case 4:
A CS where one of the participant is focus and the SRC is a different
entity like B2BUA. In this case the participant which is focus MAY
send "isfocus" in SIP message to SRC. The SRC MAY subscribe to
conference event package on seeing this "isfocus". SRC SHALL learn
the details of other participants of conference from the conference
package and send the same in metadata to SRS. The instance diagram
for this use case SHALL be same as Case 1.
+--------------------------------+
| Conference Event Package |
| |
+--------------------------------+
|
| subscribes
|
+---------------------|-----------------------------+
| Communication |Session |
| +-------------+ +------+ +--------------+ |
| | | | (SRC)| | | |
| |Participant B|--|B2BUA |----| Participant A| |
| | (FOCUS in | +------+ | | |
| | conf) | | | |
| +-------------+ +--------------+ |
| | | | | |
+---------------------------------------------------+
| | | |
| | | |
D E F G (Participants of Conference)
Ravindranath, et al. Expires December 22, 2011 [Page 21]
Internet-Draft SIP Recording Metadata June 2011
6. Security Considerations
The metadata information sent from SRC to SRS MAY reveal sensitive
Information about different participants of CS. 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 model defined in this
document. The security considerations for this SHALL be defined in
the solution document.
7. IANA Considerations
Not Applicable
8. Acknowledgement
We wish to thank John Elwell, Henry Lum, Leon Portman, De Villers,
Andrew Hutton, Deepanshu Gautam, Charles Eckel, Muthu Arul for their
valuable comments.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
9.2. Informative References
[I-D.ietf-siprec-req]
Rehor, K., Portman, L., Hutton, A., and R. Jain, "Use
Cases and Requirements for SIP-based Media Recording
(SIPREC)", draft-ietf-siprec-req-12 (work in progress),
June 2011.
[I-D.ietf-siprec-architecture]
Hutton, A., Portman, L., Jain, R., and K. Rehor, "An
Architecture for Media Recording using the Session
Initiation Protocol", draft-ietf-siprec-architecture-02
(work in progress), April 2011.
Ravindranath, et al. Expires December 22, 2011 [Page 22]
Internet-Draft SIP Recording Metadata June 2011
Authors' Addresses
Ram Mohan Ravindranath
Cisco Systems, Inc.
Cessna Business Park,
Kadabeesanahalli Village, Varthur Hobli,
Sarjapur-Marathahalli Outer Ring Road
Bangalore, Karnataka 560103
India
Email: rmohanr@cisco.com
Parthasarathi Ravindran
Cisco Systems, Inc.
Cessna Business Park,
Kadabeesanahalli Village, Varthur Hobli,
Sarjapur-Marathahalli Outer Ring Road
Bangalore, Karnataka 560103
India
Email: partr@cisco.com
Paul Kyzivat
Cisco Systems, Inc.
1414 Massachusetts Avenue
Boxborough, MA 01719
USA
Email: pkyzivat@cisco.com
Ravindranath, et al. Expires December 22, 2011 [Page 23]
