ISO/IEC TR 11802-1:1997
(Main)Information technology — Telecommunications and information exchange between systems — Local and metropolitan area networks — Technical reports and guidelines — Part 1: The structure and coding of Logical Link Control addresses in Local Area Networks
Information technology — Telecommunications and information exchange between systems — Local and metropolitan area networks — Technical reports and guidelines — Part 1: The structure and coding of Logical Link Control addresses in Local Area Networks
Technologies de l'information — Télécommunications et échange d'information entre systèmes — Réseaux locaux et métropolitains — Rapports techniques et lignes directrices — Partie 1: Structure et codage des adresses de contrôle de liaison logique dans les réseaux locaux
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Standards Content (Sample)
ISO/IEC
TECHNICAL
TR 11802-I
REPORT
Second edition
1997-08-I 5
Information technology -
Telecommunications and information
exchange between systems - Local and
metropolitan area networks - Technical
reports and guidelines -
Part 1:
The structure and coding of Logical Link
Control addresses in Local Area Networks
Technologies de I ‘information - T6I&ommunications et &change
Mseaux locaux et mktropolitains -
d ’informatlon entre systgmes -
Rapports techniques et lignes directrices -
Partie I: Structure et codage des adresses de contrble de liaison logique
dans /es r&eaux locaux
Reference number
lSO/IEC TR 11802-I :I 997(E)
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ISOAEC TR 118024 :1997(E)
Contents Page
. . .
.~.,. “. III
Foreword
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. iv
1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “.~. 1
2. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 1
3. Abbreviations
4. General considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 2
4 1 Functions of LLC addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
412. Binary and Hexadecimal representation of LLC addresses . . . . . . . . . . .~. 2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .=.~. 2
4.2.1 Binary representation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 2
4.2.2 Hexadecimal representation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.2.3 Bit order of transmission
4.3 The null address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~.~. 3
4.3.1 Function of the null address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .=.~. 3
4.3.2 Definition of the null address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.4. The global address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*. 3
4.4.1 Function of the global address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*.*. 3
Definition of the global address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.4.2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.5 The address used in conjunction with ISO/IEC TR 9577
4
4.6 The address used in conjunction with SNAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*.
5. Unreserved addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*. 4
6. Reserved addresses
.................................................................... 4
7. Procedures for assignment of reserved addresses
7.1 General considerations . 4
7.2 Specific procedures . 4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*. 6
8. LLC address assignments
Tables
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*.*. 6
Table 1 - Individual LLC address values
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 2 - Group LLC address values 8
Annexes
.......................................................................... 10
A General format of ISO/IEC 8802-2 addresses
11
B IEEE 802 - Sub-Network Access Protocol (SNAP) .
C Guidelines for requesting an LLC address value . 12
0 ISO/IEC 1997
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
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publisher.
lSO/IEC Copyright Office l Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
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ISOAEC TR 11802-l : 1997(E)
0 ISOAEC
Foreword
IS0 (the International Organization for Standardization) and IEC (the
International Electrotechnical Commission) form the specialised system for
worldwide standardisation. National bodies that are members of IS0 or IEC
participate in the development of International Standards through technical
committees established by the respective organisation to deal with particular
fields of technical activity. IS0 and IEC technical committees collaborate in
fields of mutual interest. Other international organisations, governmental
and non-governmental, in liaison with IS0 and IEC, also take part in the
work.
In the field of information 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 of one of the following types:
1, when the required support ca .nnot be obtained for the publication
- type
repeated efforts;
of an International Standard, despite
-
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 11802-1, which is a Technical Report of type 3, was prepared
by ISOAEC JTC 1, information technology, Subcommittee SC 6,
Telecommuni-cations and information exchange between systems.
This second edition cancels and replaces the first edition (ISO/IEC TR
118024 :I 995), which has been technically revised.
ISOAEC 11802 consists of the following parts, under the general title
lnforma tion technology - Telecommunications and information exchange
between systems - Local and metropolitan area networks - Technical
repotis and guidelines:
-
Part I: The structure and coding of Logical Link Control addresses in
Local Area Networks [Technical Report]
- Pati 2: Standard Group MAC Addresses [Technical Report]
- Part 4: Token ring access method and physical layer specifications -
Fibre optic station attachment
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ISOAEC TR 118024 : 1997(E) 0 ISOAEC
lntrod uction
The standards for LANs are generally comprised of the physical layer, the
medium access control (MAC) sublayer, and the logical link control (LLC)
sublayer. In OSI terminology, the MAC and LLC sublayers are considered
to be sublayers of the OSI data link layer. Both the MAC and LLC sublayers
contain fields for addressing.
This Technical Report contains a description of the LLC addresses, together
with a list of those values in current use.
The addressing space in LLC is limited, and it is such that it is considered to
be a scarce resource. It is therefore prudent to consume this resource in a
To this end this Technical Report
considered and conservative manner.
indicates the kind of considerations which will be used by ISO/IEC when
making the association between a particular LLC address value and use to
which it is put. These considerations are intended to be sufficiently broad to
allow a wide variety of LLC address uses to be recorded, and also
sufficiently restrictive so that addresses values are not unwisely assigned.
This Technical Report will be kept up to date by ISO/IEC JTC 1 as new
entries are added to the tables.
iv
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ISO/IEC TR 11802-l :1997(E)
TECHNICAL REPORT 0 ISO/IEC
Information technology -Telecommunications and
information exchange between systems - Local and metropolitan
area networks -Technical reports and guidelines -
IPart 1:
The structure and coding of Logical Link Control addresses in Local
Area Networks
1. Scope
This Technical Report provides:
a) a description of the ISO/IEC 8802-2 LLC addressing conventions,
b) the consideration for the manner in which new LLC address uses are assigned an entry in this
Technical Report, and
a record, in the form of a table, of assigned uses of ISO/IEC 8802-2 LLC address values.
C)
This Technical Report is for use by implementers to ascertain the value, or values, of LLC addresses that have
been assigned for use in a particular circumstance.
It is outside the scope of this Technical Report to provide architectural judgements regarding the entities which
are identified by particular address value(s).
2. References
ISO/IEC TR 9577: 1996, Information technology - Protocol identification in the network layer.
ISO/IEC 8802-2: 1994, Information technology - Telecommunications and information exchange between
systems - Local and metropolitan area networks - Specific requirements - Part 2: Logical link control.
3. Abbreviations
The following abbreviations are used in this Technical Report.
DSAP Destination Service Access Point
IEEE Institute of Electrical and Electronics Engineers
LLC Logical Link Control
PDU Protocol Data Unit
SAP Service Access Point
SNAP Sub-Network Access Protocol
SSAP Source Service Access Point
LSAP Link Service Access Point
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lSO/IEC TR 11802-l : 1997(E) 0 ISOAEC
4. General considerations
4.1 Functions of LLC addresses
Logical Link Control (LLC) protocol data units contain addressing information. This addressing information
consists of two fields; the Destination Service Access Point (DSAP) address field, and the Source Service
Access Point (SSAP) address field. Each of these is an 8 bit field and each is made up of two components.
In the DSAP address field, the components are an adc9ress hype designation bit, and seven bits of acfual
address. When the address type designation bit is set to ‘0 ’, it denotes that the actual address is an individual
address. When the address type designation bit is set to ‘1 I, it denotes that the DSAP actual address is a group
address. This Technical Report considers and records the two types of actual address separately.
In the SSAP address field, the components are the command/response identifier actual
bit, and seven bits of
address. The actual address in the SSAP f ‘ield is a .Iways an individual address.
Table 1 is a record of individual address values and is applicable to SSAP actual addresses, and DSAP
individual actual addresses. Table 2 is a record of DSAP group actual addresses.
In the general case, an individual actual address identifies a protocol, or set of protocols, in the next higher
layer. In OSI environments, the next higher layer is the Network Layer. In non-OS1 environments, the next
higher layer is dependent on the architecture in use.
There are certain exceptions to this general rule as discussed below.
NOTES
1. The terms in italics, namely; address type designation bit, command/response identifier bit and actual address are as
defined in lSO/IEC 8802-2. See ISO/IEC 8802-2 clause 3.3.1 .I items (2), (3), and (4).
2. The format of LLC addresses is defined in ISO/IEC 8802-2. For information this is reproduced in Annex A.
3. An individual actual address value does not necessarily have any relationship with a group address of the same actual
address value.
4.2 Binary and Hexadecimal representation of LLC addresses
4.2.1 Binary representation
The seven-bit LLC actual address value is conveyed in the eight-bit DSAP/SSAP fields and therefore can be
represented in a sequence of eight binary digits. The least significant digit is shown to the left and the
significance of the digits increases from left to right. The least significant digit of the sequence represents the
address type designation bit of the DSAP address field and the command/response identifier bit of the SSAP
address field, see figure A.I.
The following are the two permitted binary representations of an example individual actual address;
0111 1011
2111 1011.
The following is the permitted binary representation of an example group actua/ address;
1101 0101.
4.2.2 Hexadecimal representation
The eight-bit binary representation of an actual address value may be represented as two hexadecimal digits
encoding the value of the octet address field with the least significant bit set to 0 in the case of an individual
address and the least significant bit set to 1 in the case of a group address.
The following is the permitted hexadecimal representation of the example individual actual address shown in
clause 4.2.1 (Zlll 1011);
DE/DF.
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ISOAEC TR 11802-l :1997(E)
0 ISOAEC
The following is the permitted hexadecimal representation of the example group actual address shown in 4.2.1
(1101 0101);
AB.
4.2.3 Bit order of transmission
The order of transmission of bits or other components of the octet address field by any particular MAC is outside
the scope of this Technical Report which describes LLC address values in terms of the significance of individual
bits.
4.3 The null address
Function of the null address
4.3.1
The null LLC address designates the LLC entity associated with the underlying MAC SAP. The null address
does not identify any higher layer protocol nor the LLC sublayer management entity.
The null address is only valid for use in the address fields of XID and TEST PDUs. The use of the null address
(DSAP and SSAP) is specified in ISO/IEC 8802-2.
4.3.2 Definition of the null address
The null address (DSAP and SSAP) is defined in ISO/IEC 8802-2.
The null LLC address is included in table 1.
4.4 The global address
4.4.1 Function of the global address
The global LLC address is an address reserved from the range of group addresses (see table 2) and is used to
identify all LSAPs at the station identified by the MAC address.
4.4.2 Definition of the global address
The global LLC (DSAP) address is defined in ISO/IEC 8802-2.
The global LLC address is included in table 2.
The global address can only exist as a DSAP address. The individual actual address value ‘111 1111’ in DSAP and
NOTE -
SSAP address fields is a different address and should not be confused with the global address.
4.5 The address used in conjunc
...
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