ISO/IEC 14476-4:2010

Information technology — Enhanced communications transport protocol: Specification of QoS management for duplex multicast transport — Part 4:

ISO/IEC 14476-4:2010 provides a specification of QoS management for accomplishing desirable QoS for a duplex multicast transport connection. For this purpose, it describes the QoS management operations in duplex multicast transport connection such as QoS negotiation, QoS monitoring and QoS maintenance. ISO/IEC 14476-4:2010 is an integral part of ECTP-3 (ITU-T Rec. X.607 | ISO/IEC 14476-3). All of the protocol components, including packet formats and protocol procedures specified in ITU-T Rec. X.607 | ISO/IEC 14476-3 are also valid in ISO/IEC 14476-4:2010.

Technologies de l'information — Protocole de transport de communications amélioré: Spécification de la gestion de QoS pour le transport duplex en multidiffusion — Partie 4:

General Information

• Status: Published
• Publication Date: 18-Apr-2010
• ICS: 35.100.40 - Transport layer
• Technical Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Drafting Committee: ISO/IEC JTC 1/SC 6/WG 7 - Network, transport and future network
• Current Stage: 9093 - International Standard confirmed
• Start Date: 23-May-2025
• Completion Date: 24-May-2025

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 14476-4
First edition
2010-05-01
Information technology — Enhanced
communications transport protocol:
Specification of QoS management for
duplex multicast transport
Technologies de l'information — Protocole de transport de
communications amélioré: Spécification de la gestion de QoS pour le
transport duplex en multidiffusion

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

CONTENTS
Page
1 Scope. 1

2 Normative references . 1
3 Definitions . 1

3.1 Terms defined in Rec. ITU-T X.605 | ISO/IEC 13252 . 1
3.2 Terms defined in Rec. ITU-T X.606 | ISO/IEC 14476-1. 1
3.3 Terms defined in Rec. ITU-T X.606.1 | ISO/IEC 14476-2. 2
3.4 Terms defined in Rec. ITU-T X.607 | ISO/IEC 14476-3. 2
4 Abbreviations . 2
4.1 Packet types. 2
4.2 Miscellaneous . 3
5 Overview. 3
6 Components for QoS management. 5
6.1 Base header. 5
6.2 QoS parameters . 6
6.3 QoS extension element. 7
6.4 Acknowledgement element . 7
6.5 Packets used for QoS management . 8
7 QoS negotiation for duplex multicast connection . 8
7.1 Negotiation procedures. 9
7.2 QoS negotiation in the tree hierarchy . 10
7.3 Resource reservation. 10
8 QoS monitoring and maintenance for the forward channel . 10
8.1 QoS monitoring for the forward multicast channel. 11
8.2 QoS maintenance for the forward multicast channel. 13
9 QoS monitoring and maintenance for the backward channel. 15
9.1 QoS monitoring for the backward unicast channel . 15
9.2 QoS maintenance for the backward unicast channel . 16
Annex A – Implementation considerations. 18

© 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 14476-4 was prepared by ITU-T (as ITU-T Rec. X.607.1) and was adopted, under a special
“fast-track procedure”, by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with
its approval by the national bodies of ISO and IEC. The identical text is published as ITU-T
Rec. X.607.1 (11/2008).
ISO/IEC 14476 consists of the following parts, under the general title Information technology — Enhanced
communications transport protocol:
⎯ Part 1: Specification of simplex multicast transport
⎯ Part 2: Specification of QoS management for simplex multicast transport
⎯ Part 3: Specification of duplex multicast transport
⎯ Part 4: Specification of QoS management for duplex multicast transport
⎯ Part 5: Specification of N-plex multicast transport
⎯ Part 6: Specification of QoS management for N-plex multicast transport

iv © ISO/IEC 2010 – All rights reserved

Introduction
This Recommendation | International Standard specifies the Enhanced Communications Transport Protocol (ECTP),
which is a transport protocol designed to support Internet multicast applications running over multicast-capable
networks. ECTP operates over IPv4/IPv6 networks that have the IP multicast forwarding capability with the help of

IGMP and IP multicast routing protocols, as shown in Figure 1. ECTP could possibly be provisioned over UDP.

Figure 1 – ECTP Model
ECTP is designed to support tightly controlled multicast connections in simplex, duplex and N-plex applications.
ECTP part 4 QoS management (this Recommendation | International Standard) specifies the quality of service (QoS)
management functionality for stable management in the duplex multicast connection. The QoS management
functionality consists of QoS negotiation, QoS monitoring and QoS maintenance operations. The procedures of
reliability control in duplex connection have been defined in ECTP part 3 (Recommendation ITU-T X.607 |
ISO/IEC 14476-3).
In ECTP-3 duplex multicast connection, the participants are classified into one Transport Connection Owner
(TC-Owner) and many Transport Services users (TS-users). TC-Owner will be designated among the TS-users before
the connection begins. In the duplex multicast connection, the two types of data transports are supported: multicast data
transport from TC-Owner to all the other TS-users and unicast data transport from TS-users to TC-Owner. After the
connection is created, TC-Owner can transmit multicast data to the group, whereas each TS-user is allowed to send
unicast data to TC-Owner just after it gets a token from the TC-Owner.
For QoS management in the duplex multicast connection, the TC-Owner triggers the connection creation process. Some
or all of the enrolled TS-users will participate in the connection and become the designated "active TS-users". The
TS-users who are active at this stage are able to participate in negotiating the desired QoS level for the session. In the
duplex multicast connection, TS-users can send the data to TC-Owner, which each TS-user negotiates with TC-Owner
for a QoS parameter for backward unicast data channel. TC-Owner proposes the target value of QoS parameter for
forward multicast data channel and backward unicast data channel. If QoS negotiation is enabled, each TS-user can
propose modified values of QoS parameters for forward multicast data channel and backward unicast data channel.
TC-Owner arbitrates these modified values of QoS parameters for two types of data transport. These arbitrated values
are delivered to TS-users via subsequent Heartbeat (HB) or Join Confirm (JC) packets, and will be used for QoS
monitoring and maintenance. Any enrolled TS-user that is not active at this stage may participate in the connection as a
late-joiner, but will have to accept the established QoS level.
After the connection is created, TC-Owner begins to transmit multicast data and some of TS-users who get a token from
TC-Owner can send unicast data to TC-Owner. While the connection is active, TC-Owner monitors the status of the
session via feedback control packets from the active TS-users.
TC-Owner may take a range of actions if network problems (such as severe congestion) are indicated by the feedback
received from active TS-users. These actions include adjusting the data transmission rate, suspending multicast data
transmission temporarily, or in the last resort, terminating the connection.
ECTP part 4 QoS management Specification can be used by the multicast applications that require supporting various
QoS requirements and the corresponding billing/charging models.

© ISO/IEC 2010 – All rights reserved v

INTERNATIONAL STANDARD
RECOMMENDATION ITU-T
Information technology – Enhanced communications transport
protocol: Specification of QoS management
for duplex multicast transport
1 Scope
This Recommendation | International Standard provides a specification of QoS management for accomplishing
desirable QoS for a duplex multicast transport connection. For this purpose, this Specification describes the QoS
management operations in duplex multicast transport connection such as QoS negotiation, QoS monitoring and QoS
maintenance. This Recommendation | International Standard is an integral part of ECTP-3 (Rec. ITU-T X.607 |
ISO/IEC 14476-3). All of the protocol components, including packet formats and protocol procedures specified in
Rec. ITU-T X.607 | ISO/IEC 14476-3, are also valid in this Recommendation | International Standard.
2 Normative references
The following Recommendations and International Standards contain provisions which, through reference in this text,
constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated
were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this
Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent
edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently
valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently
valid ITU-T Recommendations.
– Recommendation ITU-T X.601 (2000), Multi-peer communications framework.
– Recommendation ITU-T X.602 (2004) | ISO/IEC 16513:2005, Information technology – Group
management protocol.
– Recommendation ITU-T X.605 (1998) | ISO/IEC 13252:1999, Information technology – Enhanced
Communications Transport Service Definition.
– Recommendation ITU-T X.606 (2001) | ISO/IEC 14476-1:2002, Information technology – Enhanced
Communications Transport Protocol: Specification of simplex multicast transport.
– Recommendation ITU-T X.606.1 (2003) | ISO/IEC 14476-2:2003, Information technology – Enhanced
Communications Transport Protocol: Specification of QoS management for simplex multicast transport.
– Recommendation ITU-T X.607 (2007) | ISO/IEC 14476-3:2008, Information technology – Enhanced
communications transport protocol: Specification of duplex multicast transport.
– Recommendation ITU-T X.608 (2007) | ISO/IEC 14476-5:2008, Information technology – Enhanced
communications transport protocol: Specification of N-plex multicast transport.
3 Definitions
3.1 Terms defined in Rec. ITU-T X.605 | ISO/IEC 13252
This Recommendation | International Standard is based on the concepts developed in Enhanced Communications
Transport Service (Rec. ITU-T X.605 | ISO/IEC 13252):
a) QoS parameters;
b) QoS neg
...