ISO/IEC TR 9577:1993

Information technology — Telecommunications and information exchange between systems — Protocol identification in the network layer

Technologies de l'information — Télécommunications et échange d'informations entre systèmes — Identification du protocole dans la couche réseau

General Information

• Status: Withdrawn
• Publication Date: 29-Sep-1993
• Withdrawal Date: 29-Sep-1993
• ICS: 35.100.30 - Network layer
• Technical Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Drafting Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 26-Dec-1996

Relations

• Revised: ISO/IEC TR 9577:1996 - Information technology — Protocol identification in the network layer
• Effective Date: 15-Apr-2008

Standards Content (Sample)

ISO/IEC
TECHNICAL
TR 9577
REPORT
Second edition
1993- 1 O- 15
Information technology - Telecommunications and
information exchange between systems - Protocol
identification in the network layer
Technologies de l'information -Télécommunications et échange d'informations
entre systèmes - Identification du protocole dans la couche réseau
Reference number
ISO/IEC TR 9577:1993 (E)

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O ISO/IEC
ISOllEC TR 9577 : 1993 (E)
Foreword
IS0 (the International Organization for Standardization) and IEC (the International Electrotechiiical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of IS0 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. IS0 and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, governmental and non-governmental, in liaison with IS0 and IEC, also
take part in the work.
In the field of informabon technology, IS0 and IEC have established a joint technical committee,
ISOAEC JTC 1
The main task of technical committees is to prepare International Standards, but in exceptional
circumstances a technical committee may propose the publication of a Technical Report ot one of
the following types
-
type 1, when the required support cannot be obtained for the publication of an International
Standard, despite repeated efforts;
-
type 2, when the subject is still under technical development or where for any other reason
there is the future but not immediate possibility of an agreement on an International Standard;
-
type 3, when a technical committee has collected data of a different kind from that which is
normally published as an International Standard ('state of the art', for example).
Technical Reports of types 1 and 2 are subject to review within three years of publication, to
decide whether they can be transformed into International Standards. Technical Reports of type 3
do not necessarily have to be reviewed until the data they provide are considered to be no longer
valid or useful.
ISOAEC TR 9577, which is a technical report of type 3, was prepared by Joint Technical
Committee ISO/IEC JTC 1, lnformation technology, Sub-committee 6, Telecommunications and
information exchange between systems.
This second edition cancels and replaces the first edition (ISO/IEC TR 9577:1990), which has
been technically revised.
O ISOAEC 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission
in writing from the publisher.
lSO/IEC Copyright Office * Case postale 56 CH-I211 Genève 20 Switzerland
Printed in Switzerland
ii

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O ISOAEC
ISO/IEC TR 9577 : 1993 (E)
Introduction
Identifying protocols by information in a uniform part of the protocol control information
fulfils two requirements:
I. It enables an entity to verify that the protocol received is of the
type and kind expected; and
ii.
It permits an entity to discriminate among a number of different
protocols (both OS1 and non-OSI) that might Co-exist in a
common environment.
This Technical Report contains a description of the means used to identify
protocols and where that information is located in a protocol, together with a
record of those values of protocol identifiers which have been used by IS0 and
by other authorities. This document does not attempt to provide any general
architectural principles for the functions of the protocol identification, nor does it
attempt to provide judgements as to whether a protocol might have more than
one value of protocol identifier.
By reference to this Technical Report, future protocols can be developed to
be
include a protocol identifier and the value(s) of the protocol identifier can
chosen on a knowledgeable basis.
This Technical Report notes that CCITT Recommendation X.244 provides the
basis for subclause 6.2.

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TECHNICAL REPORT O ISO/IEC ISO/IEC TR 9577 : 1993 (E)
Information technology - Telecommunications and
information exchange between systems - Protocol
identification in the network layer
2 References
O ' Scope
This Technical Report provides ISOiI EC 8073 : 1992, Information technology - Telecommunications
and information exchange between systems - Open Systems
Interconnection - Protocol for providing the connection-mode
a) the description of a means to permit a protocol to be identified;
transport service.
b) a record of the structure and allowable ranges of protocol
NOTE - See also CCITT Recommendation X.224.
identifier@) which can be assigned by ISOiIEC JTC1 SC6,
CCITT and other authorities;
ISOiIEC 8208 : 1990, Information technology - Data communications
- X.25 Packet Layer Protocol for Data Terminal Equipment.
c) a record of the values of protocol identifiers used by OS1
Network Layer protocols and non-OS1 protocols occupying a
NOTE - See also CCITT Recommendation X.25
similar position, in particular, only protocols with protocol
control information commencing in octet 1 of the protocol data
unit are covered; and IS0 8473 : 1988, Information processing systems - Data communi-
cations - Protocol for providing the connectionless-mode network
service.
d) a record of the values that are in use as protocol control
information in non-Network Layer protocols where they impact
on Network Layer protocol identification. ISOiIEC 8878- 1 : 1992, Information technology - Telecommunications
and information exchange between systems - Use of X.25 to provide
the OS1 Connection-Mode Network Service.
The application of this Technical Report is
NOTE - See also CCITT Recommendation X.223.
a) in the identification of internationally standardized Network
Layer protocols operating directly above the Data Link Service;
0
ISO/IEC 8880-2 ' 1992, Information technology - Telecommunications
and information exchange between systems - Protocol combinations
b) in the identification of protocols used in conjunction with
to provide and support the OS1 Network Service - Part 2: Provision
internationally standardized Network Layer protocols that
and support of the connection-mode Network Service.
operate directly above the Data Link Service; and
ISO/IEC 8880-3 : 1990, Information technology - Telecommunications
c) to distinguish between Internationally standardized Network
and information exchange between systems - Protocol combinations
Layer protocols, and other internationally standardized
to provide and support the OS1 Network Service - Part 3: Provision
protocols used in conjunction with internationally standardized
and support of the connectionless-mode Network Service.
Network Layer protocols.
ISO/IEC 9542 : 1988, Information processing systems - Telecommu-
This Technical Report is for use by ISO/IEC Technical Committees
nications and information exchange between systems - End sysilem
and other authorities in applying the principles contained in clause 4,
to Intermediate system routeing exchange protocol for use in con-
and in selecting an unused value or values from the range of values
junction with the Protocol for providing the connectionless-mode
permitted in clause 5 or clause 6, as appropriate. When a new value
network service (IS0 8473).
is selected, that value and its usage should be brought to the
attention of ISOiIEC JTC 1 SC6 so that this Technical Report can be
amended. ISOiIEC 10030 : 1990, Information technology - Telecommunications
and information exchange between systems - End System Routeing
Information Exchange Protocol for use in conjunction with IS0 8878.
1

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O ISO/IEC
ISO/IEC TR 9577 : 1993 (E)
PDU Protocol Data Unit
ISO/IEC 10589 : 1992, Information technology - Telecommunications
and information exchange between systems - Intermediate system to
intermediate system intra-domain routeing routine information
SPI Subsequent Protocol Identifier
exchange protocol for use in conjunction with the protocol for
8473).
providing the connectionless-mode Network Service (IS0
TPDU Transport Protocol Data Unit
ISO/IEC 10747 :l) Information technology - Telecommunications and
TR Technical Report
information exchange between systems - Protocol for exchange of
inter-domain routeing information among intermediate systems to
support forwarding of IS0 8473 PDUs.
4 Protocol identifiers
ISO/IEC 11570 :l) Information technology - Telecommunications and
The protocol operating directly over the Data Link Layer is termed
information exchange between systems - Open Systems Intercon-
initial protocol and is identified by the Initial Protocol Identifier (IPI)
nection - Transport Protocol Identification Mechanism.
The protocol carried by the initial protocol is termed the subsequent
ISO/IEC 11577 :l) Information technology - Telecommunications and
protocol and is identified by a Subsequent Protocol Identifier (SPI)
information exchange between systems - Network layer security
protocol.
The subsequent protocol can carry further subsequent protocols,
identified by further SPIS, iteratively
CClTT Recommendation G.764, Voice packetization - Packetized
voice protocol.
For the purpose of this Technical Report, the octets referred to as IPI
SPI are viewed as protocol identifiers In some cases the
and
CClTT Recommendation Q.93B1) Broadband ISDN Signalling
protocol itself gives other names to these octets, and might also view
protocol.
the function of the octets as being distinct from protocol identification
ISO/IEC 8208 is an example (see annex A of this Technical Report)
CClTT Recommendation Q.931, ISDN User-Network Interface Layer
It is possible to identify such protocols by the means described in this
3 Specification.
Technical Report
CCITT Recommendation Q.932, Generic Procedures for the Control
NOTE - Guidelines for the processing of protocol identifiers are given in
of ISDN Supplementary Services. Annex B
CClTT Recommendation Q.933, Signalling Specification for Frame
5 Initial protocol identifier
Mode Bearer Service.
5.1 General
CClTT Recommendation T.70, Network-independent basic transport
service for the telematic setvices.
The location of the IPI is the first octet of the protocol control
information, this is depicted in figure 1 The value of the IPI
CClTT Recommendation X.29, Procedures for the exchange of
unambiguously identifies the initial protocol
control information and user data between a packet
assembly/disassembly facility (PAD) and a packet mode DTE or
another PAD.
ûata Link
data unit
sei~ice
__---
< -->
CClTT Recommendation X.39. Procedures for the exchange of
control information and user data between a facsimile packet
Octet 1
assembly/disassembly (FPAD) facility and a packet mode DTE or
-
another FPAD.
Li-
TF
ai
CCITT Recommendation X.244, Exchange of protocol identification
during virtual call establishment on Packet Switched Public Data
-
Networks.
A
3 Abbreviations
Network Layer
prütoctrlcür&rol irhmtbn
CCITT International Telegraph and Telephone Consultative
Location /- d thelPl
Committee
GFI General Format Identifier
Figure 1 - Location of the IPI
IPI Initial Protocol Identifier
5.2 Assignment structure
NCMS Network Connection Management Subprotocol
The structure applied to the values of the IPI is depicted in table 1.
OS1 Open Systems Interconnection
1) To be published.
2

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O ISO/IEC ISO/IEC TR 9577 : 1993( E)
With the exception of protocol identifiers used by ISOiIEC 8208 (and 6.2 Assignment structure
CClTT Recommendation X.25), bits 8, 7, 6, and
by the corresponding
5 of the IPI indicate the administrative authority which is responsible
The structure applied to the SPI is depicted in Table 3.
for assigning a combination of the associated bits 4, 3, 2, and 1 to an
initial protocol.
Bits 8 and 7 of the SPI indicate the administrative authority (if any)
which is responsible for assigning the associated bits 6, 5, 4, 3, 2,
5.3 Values assigned to the IPI
and 1 to a subsequent protocol.
Table 2 records the values that have been assigned to specific
6.3 Values assigned to the SPI
protocols. Values not recorded are reserved and available for
allocation by the administrative authorities specified by the structure
depicted in clause 5.2. Table 4 records the values that have been assigned to specific
protocols which operate over the initial protocol. Values not recorded
are reserved and available for allocation by the administrative
A specific value is reserved to indicate the null Network Layer. One
authorities specified by the structure depicted in clause 6.2.
value is reserved for future extension to this Technical Report.
6 Subsequent protocol identifier
Data Link
service data unit
6.1 General
- I - - - -
<
Octet
The SPI is the first octet of protocol control information in each
instance of communication of the subsequent protocol. This is
depicted in figure 2 where a subsequent protocol is operating directly
l'j -
over the initial protocol.
The value of the SPI:
I
Next highest sublayer
identifies another OS1 Network Layer
of the NetworkLayet,
protocol;
identifies some other non-OS1 protocol;
Location oft he SPI
or
NOTE. The term sublayer is used as defined in IS0 7498-1
is that which is in use by an OS1
Transport Layer protocol.
Figure 2 - Location of the SPI
It should be noted that in some cases an SPI might not be present,
A.3.
for example see
3

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