ISO/IEC 24792:2010

INTERNATIONAL ISO/IEC
STANDARD 24792
First edition
2010-04-15
Information technology —
Telecommunications and information
exchange between systems — Multicast
Session Management Protocol (MSMP)
Technologies de l'information — Téléinformatique — Protocole de
gestion de session de multidiffusion (MSMP)

Reference number
©
ISO/IEC 2010
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ii © ISO/IEC 2010 – All rights reserved

Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
3.1 Terms defined in ITU-T Rec. X.601 .1
3.2 Terms defined in ITU-T Rec. X.602 | ISO/IEC 16513 .1
3.3 Terms defined in ITU-T Rec. X.605 | ISO/IEC 13252 .2
3.4 Terms defined in ITU-T Rec. X.606 | ISO/IEC 14476-1.2
3.5 Terms defined in ITU-T Rec. X.606.1 | ISO/IEC 14476-2.2
3.6 Terms defined in this International Standard.2
4 Abbreviated terms.3
4.1 Message types .3
4.1.1 Session Management message types.3
4.1.2 QoS Management message types .4
4.2 Miscellaneous .4
5 Conventions.5
6 Overview.5
6.1 General MSMP .5
6.2 Session Management.5
6.3 QoS Management .6
7 Protocol operations.8
7.1 Session Management.8
7.1.1 Session creation.8
7.1.2 Session registration.8
7.1.3 Session enrollment .9
7.2 QoS Management .9
7.2.1 General QM .9
7.2.2 QoS reporting request and response.10
7.2.3 QoS setting request and response.11
7.2.4 QoS updating request and response .12
7.2.5 QoS value request and response .15
7.2.6 QoS termination request and indication.15
8 MSMP messages .16
8.1 Session Management message types and the format.16
8.2 QoS Management message types .16
8.3 QoS management message format .17
9 MSMP variables .20
9.1 Variables.20
9.2 Timer.20
Annex A (informative) Relationship between MSMP, GMP, and ECTP .21
Annex B (informative) Messages exchange between MSMP server and GMP server .22

© ISO/IEC 2010 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 24792 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
iv © ISO/IEC 2010 – All rights reserved

Introduction
Multicast Session Management Protocol (MSMP) will operate over the conventional transport protocols and/or
Enhanced Communications Transport Protocol (ECTP), as shown in Figure 1.

Figure 1 — MSMP Model (MSMP Protocol Stack)

© ISO/IEC 2010 – All rights reserved v

INTERNATIONAL STANDARD ISO/IEC 24792:2010(E)

Information technology — Telecommunications and information
exchange between systems — Multicast Session Management
Protocol (MSMP)
1 Scope
This International Standard provides a specification of a Multicast Session Management Protocol (MSMP),
which is an application-layer control protocol for managing quality of service for group communication. MSMP
consists of QoS management (QM) functions.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ITU-T Rec. X.601 (2000), Information technology — Multi-Peer Communications Framework
ITU-T Rec. X.602 (2004) | ISO/IEC 16513: 2005, Information technology — Group management protocol
ITU-T Rec. X.605 (1998) | ISO/IEC 13252:1999, Information technology — Enhanced communications
transport service definition
ITU-T Rec. X.606 (2001) | ISO/IEC 14476-1:2002, Information technology — Enhanced communications
transport protocol: Specification of simplex multicast transport
ITU-T Rec. X.606.1 (2002) | ISO/IEC 14476-2:2003, Information technology — Enhanced communications
transport protocol: Specification of QoS management for simplex multicast transport
3 Terms and definitions
3.1 Terms defined in ITU-T Rec. X.601
For the purposes of this document, the following terms defined in ITU-T Rec. X.601 apply:
a) multi-peer;
b) multi-peer communication;
c) multicast transmission.
3.2 Terms defined in ITU-T Rec. X.602 | ISO/IEC 16513
For the purposes of this document, the following terms defined in ITU-T Rec. X.602 | ISO/IEC 16513 apply:
a) GMP client;
© ISO/IEC 2010 – All rights reserved 1

b) GMP server;
c) session creator;
d) session client;
e) session participant.
3.3 Terms defined in ITU-T Rec. X.605 | ISO/IEC 13252
For the purposes of this document, the following terms defined in ITU-T Rec. X.605 | ISO/IEC 13252 apply:
a) enrolled group;
b) active group;
c) TC-owner.
3.4 Terms defined in ITU-T Rec. X.606 | ISO/IEC 14476-1
For the purposes of this document, the following terms defined in ITU-T Rec. X.606 | ISO/IEC 14476-1 apply:
a) TO (top owner);
b) LO (local owner);
c) LE (leaf entity).
3.5 Terms defined in ITU-T Rec. X.606.1 | ISO/IEC 14476-2
For the purposes of this document, the following terms defined in ITU-T Rec. X.606.1 | ISO/IEC 14476-2
apply:
a) QoS monitoring;
b) QoS maintenance.
3.6 Terms defined in this International Standard
For the purposes of this document, the following terms and definitions apply.
3.6.1
MSMP server
application program that is responsible for QoS management
NOTE The MSMP server will aggregate the QoS parameter values from all session participants and arbitrate the
QoS parameter values. After arbitration, the MSMP server will announce the arbitrated QoS parameter values to all
session participants. The MSMP server will keep and update the QoS parameter values.
3.6.2
MSMP client
application program that sends and receives MSMP messages
NOTE Clients store and acquire information through a MSMP server. All clients need to log in to the server to acquire
information from the server. Clients are largely divided between a session creator and session participants.
2 © ISO/IEC 2010 – All rights reserved

3.6.3
session creator
client who creates and who may terminate a session
NOTE 1 The session creator is defined in ITU-T Rec. X.602 | ISO/IEC 16513.
NOTE 2 The session creator is the sender and sends the QoS parameter values for the traffic characteristics of the
data that the sender will transmit to receivers.
3.6.4
session participant
client who registers for a session intending to participate in that session, and who, after registration, will join
the session to be an active member
NOTE 1 A session participant may be a sender in the session.
NOTE 2 The session participant has to respond to a QoS Reporting Request message, QRREQ, via a QoS Reporting
Response message, QRRES.
NOTE 3 A session participant may be a TC-participant defined in ITU-T Rec. X.605 | ISO/IEC 13252, ECTS.
4 Abbreviated terms
4.1 Message types
4.1.1 Session Management message types
The session management message types are defined in ITU-T Rec. X.602 | ISO/IEC 16513.
SCREQ Session Creation Request message
SCACC Session Creation Acceptance message
SCREJ Session Creation Reject message
SDREQ Session Deletion Request message
SDRES Session Deletion Response message
SCINF Session Creation Information message
SCCON Session Creation Confirm message
SRREQ Session Registration Request message
SRACC Session Registration Acceptance message
SRREJ Session Registration Reject message
SRRES Session Registration Response message
SJREQ Session Join Request message
SJRES Session Join Response message
SAREQ Session Activation Request message
© ISO/IEC 2010 – All rights reserved 3

4.1.2 QoS Management message types
QRREQ QoS Reporting Request message
QRRES QoS Reporting Response message
QSREQ QoS Setting Request message
QSRES QoS Setting Response message
QSREP QoS Setting Report message
QUREQ QoS Updating Request message
QURES QoS Updating Response message
QVREQ QoS Value Request message
QVRES QoS Value Response message
QTREQ QoS Termination Request message
QTIND QoS Termination Indication message
QSCREQ QoS Session Creation Request message
QSCACC QoS Session Creation Acceptance message
QSCCON QoS Session Creation Confirm message
QSJIND QoS Session Join Indication message
4.2 Miscellaneous
ECTP Enhanced Communications Transport Protocol
ECTS Enhanced Communications Transport Service
GMP Group Management Protocol
SM Session Management
MM Membership Management
RMT Reliable Multicast Transport
SAP Session Announcement Protocol
SDP Session Description Protocol
IP Internet Protocol
CHQ Controlled Highest Quality
OT Operating Target
LQA Lowest Quality Allowed
MSS Maximum Segment Size
QoS Quality of Service
RSVP Resource Reservation Protocol
4 © ISO/IEC 2010 – All rights reserved

5 Conventions
In this International Standard, the key words “MUST”, “REQUIRED”, “SHALL”, “MUST NOT”, “SHALL NOT”,
“SHOULD”, “SHOULD NOT”, “MAY”, and “OPTIONAL” are to be interpreted as described in IETF RFC 2119,
and indicate requirement levels for compliant MSMP implementations. Those key words are case-sensitive.
6 Overview
6.1 General MSMP
The MSMP is an application-layer control protocol for managing a quality of service for a group session. The
MSMP would be designed to provide the IP multicast-based multimedia applications with a QoS management
required for the group multicasting such as QoS monitoring and reporting. The MSMP will operate over the
conventional transport protocols and/or ECTP, and can be used as a control protocol together with the GMP.
Generally it is assumed that there are one MSMP server, one GMP server, one session creating client (or
Session Creator), and one or more session participating clients (or Session Participants) as shown in
Figure 2.
Figure 2 — Network Configuration for MSMP
6.2 Session Management
Session Management (SM) is a part defined in the session management (section 6.1) of ITU-T Rec. X.602 |
ISO/IEC 16513, GMP.
SM may be achieved in eight distinct phases: creation, announcement, registration, enrollment, activation, de-
registration, de-enrollment, and de-activation.
A particular client, called a session creator, creates a session. Then, SM updates the session list.
The session creator will send a Session Creation Request message, SCREQ to the GMP server with initial
QoS parameter values for a session creation. The GMP server sends the MSMP server a QoS Session
Creation Request message, QSCREQ, which includes session creation information and QoS parameter
values for a session creation. QSCREQ is to ask whether the QoS parameter values are available or not for a
session creation. Considering the network environment and its application, the MSMP server may allow the
request from the GMP server by replying with a QoS Session Creation Acceptance message, QSCACC. After
receiving QSCACC, if the session creation is possible, the GMP server sends a Session Creation Acceptance
message, SCACC. Then the session creator will send the detailed session information to the server and
receive the confirmation message with a modified and more specified QoS parameter values. The GMP
© ISO/IEC 2010 – All rights reserved 5

server reply with a Session Creation Confirm message, SCCON and then the server notifies the MSMP server
of a session creation via a QoS Session Creation Confirm message, QSCCON. If the session can not be
created or the session creator does not have the necessary rights, then a Session Creation Reject message,
SCREJ will be returned.
After successful session creation, the server will announce the new session to the clients with the more
specified QoS parameter values. The announcement may be done by e-mail, web posting, and so on. From
this point on, those clients may register in multicast groups.
A client may register for the session, considering those QoS parameter values. After successful registration,
the client belongs to the registered group.
When the session starts, the session's registered members will start a group application to send and receive
session data. At this time, all preparations for the data transfer and group management are accomplished.
The session's registered group member belongs to the enrolled group. After that, the GMP server sends the
MSMP server a QoS Session Join Indication message, QSJIND. The MSMP server starts the QoS Reporting
Request and Response.
6.3 QoS Management
The MSMP server aggregates the QoS parameter values such as throughput, delay, delay jitter, and loss from
all participants. After aggregation of the QoS parameter values, the MSMP server arbitrates them and will
send the QoS parameter values to the session creator via a QoS Setting Request message, QSREQ. The
session creator will acknowledge with the final arbitrated the QoS parameter values to the MSMP server via a
QoS Setting Response message, QSRES. After receiving QSRES, the MSMP server announces the final
arbitrated QoS parameter values to all session participants via QoS Setting Report message, QSREP.
The QoS reporting is performed to maintain and update the QoS parameter values. The MSMP server will
send periodically a QoS Reporting Request message, QRREQ, to all participants to gather the QoS
parameter values. Each participant will acknowledge with own QoS parameter values for receiving a data via
a QoS Reporting Response message, QRRES. If the session participant is a session creator or a sender, the
participant will reply with own QoS parameter values for sending and receiving data via QRRES. After
receiving QRRES, the MSMP server arbitrates them and will send the QoS parameter values to the session
creator via QSREQ. The session creator will reply with the final arbitrated the QoS parameter values to the
MSMP server via QSRES. After receiving QSRES, the MSMP server will update and keep the QoS parameter
values and announces the values to all session participants.
Figure 3 shows an example of MSMP operations. After a session is created and announced, four session
participants, A, B, C, and D register for a session in the session registration phase. The session creator and
clients send a session join request to the GMP server to be ready to communicate with each other in the
session enrollment phased. After that, the session creator and the clients belong to the enrolled group. A
session creator and three participants, A, B and D enter the active state by sending a session activation
request message to the GMP server. In Figure 3, the participant C who is a late-joiner will send a session
activation request message to the GMP server after the session activation. In the late join case, the late-joiner
comes to send a QoS Value Request message, QVREQ, to the MSMP server in order to get QoS parameter
values of the on-going session. Now, the participant D comes to be a troublemaker who reports QoS
parameter values lower than the QoS parameter values of the on-going session. If a troublemaker could not
maintain the QoS parameter values at a desired level in the on-going session, the troublemaker may be
ejected from the on-going session as shown in Figure 3. For some reason there may be a case that the
troublemaker does not leave the session( see subsection 7.2.4).
6 © ISO/IEC 2010 – All rights reserved

QSREP
Session Session Session Session
Session
GMP
MSMP
Creator Participant Participant B Participant C Participant D
Server
Server
MSMP Phase GMP Phase
(Sender) A (Sender) (Late Join) (Troublemaker)
SCREQ
QSCREQ
Session
QSCACC
SCACC
Creation
SCINF
QSCCON SCCON
Session
Announcement
SRREQ
SRACC
SRREQ
SRACC
Session
SRREQ
Registration
SRACC
SRREQ
SRACC
SJREQ
SJRES
SJREQ
SJRES
SJREQ
SJRES
SJREQ
SJRES
SJREQ
SJRES
Session
QSJIND Enrollment
QRREQ QRREQ QRREQ QRREQ
QRRES
QoS value
QRRES Collection &
QRRES Reporting
QRRES
QoS value
QSREQ Arbitration
QSRES
QoS value
Setting & Reporting
QSREP QSREP QSREP QSREP
SAREQ
KAREQ
KSRES
SAREQ
KAREQ
KARES
SAREQ
KAREQ
KARES
SAREQ
KAREQ
KARES
QRREQ QRREQ QRREQ QRREQ
QRRES
QoS value Session
QRRES
Collection & Activation
QRRES
Reporting
QRRES
QoS value
QSREQ Arbitration
QSRES
QoS value
QSREP QSREP QSREP QSREP Setting & Reporting
QVREQ
QVRES
SAREQ
Late-Join
KAREQ
KARES
QRREQ QRREQ QRREQ QRREQ     QRREQ
QRRES
QoS value
QRRES
QRRES Collection &
QRRES Reporting
QRRES
QUREQ
QURES
QUREQ
QoS value
QURES
update for
QUREQ
a troublemaker
QURES
QUREQ
QURES
KAREQ
Troublemaker
ejection
QRREQ QRREQ QRREQ QRREQ
QRRES
QoS value
QRRES
Collection &
QRRES
QRRES Reporting
QoS value
QSREQ
Arbitration
QSRES QoS value
QSREP QSREP QSREP
Setting & Reporting
QTREQ
MSMP
QTIND QTIND QTIND QTIND
Termination
TRREQ
Session
TRIND TRIND TRIND TRIND Termination

Figure 3 — An example of the MSMP control
© ISO/IEC 2010 – All rights reserved 7

7 Protocol operations
7.1 Session Management
Note: Session Management (SM) is a part defined in the session management (subsection 7.1) of ITU-T Rec.
X.602 | ISO/IEC 16513, GMP.
7.1.1 Session creation
Session creation is effected by a session creator, who will define and characterize the session with initial QoS
parameter values including media type, application type, additional information, and so on.
Figure 4 shows the successful session creation procedure. A Session Creator defines and characterizes a
session with initial QoS parameter values and sends the GMP server a Session Creation Request message,
SCREQ.
The GMP server sends the MSMP server a QoS Session Creation Request message, QSCREQ, which
includes session creation information and the QoS parameter values for a session creation. QSCREQ is to
ask whether the QoS parameter values are available or not for a session creation. Considering the network
environment and its application, the MSMP server may allow the request from the GMP server by replying
with a QoS Session Creation Acceptance message, QSCACC.
After receiving QSCACC, the GMP server considers the multicast environment and its application. If the
session creation is possible, the GMP server sends a Session Creation Acceptance message, SCACC. Then,
the Session Creator will send the GMP server detailed session information in a Session Creation Information
message, SCINF, which may include media type, application type, etc. The server will acknowledge
successful session creation with a Session Creation Confirm message, SCCON, to the session creator and
then the GMP server sends the MSMP server a QoS Session Creation Confirm message, QSCCON.

Figure 4 — Successful session creation procedure
7.1.2 Session registration
Session registration is to select a session and to let the server and creator know the intention of the
participation.
In the open mode session, the session client will select a session and send the GMP server a Session
Registration Request message, SRREQ, considering the announced QoS parameter values. The server will
simply add the requesting client to the Registered Group Membership list, and reply to the requestor with a
Session Registration Acceptance message, SRACC, as shown in Figure 5 or Figure 6 according to the
session mode. The session modes are defined in the session registration (section 7.1.3) of ITU-T Rec. X.602 |
ISO/IEC 16513, GMP.
8 © ISO/IEC 2010 – All rights reserved

Figure 5 — Successful session registration procedure (Open mode)

Figure 6 — Successful session registration procedure (Close mode)
7.1.3 Session enrollment
Session enrollment is the state where communication is possible among a session creator and session
participants. Session participants, including the session creator, should send the GMP server a Session Join
Request message, SJREQ. The server will add the participants to the Enrolled Group Membership list and
reply to the participant with a Session Join Response message, SJRES, as shown in Figure 7.
After receiving SJRES from the session creator and the session participants, the GMP server sends the
MSMP server a QoS Session Join Indication message, QSJIND to inform the MSMP server of the session
enrolled state. After the MSMP server receives QSJIND, the MSMP server will start the QoS management.

Figure 7 — Successful session enrollment procedure
7.2 QoS Management
7.2.1 General QM
QoS Management (QM) may have five operations such as QoS Report request and response, QoS Setting
request and response, QoS Updating request and response, QoS Value request and response, and QoS
Termination reques
...