ISO/IEC 8208:1990/Amd 1:1990

Information technology — Data communications — X.25 Packet Layer Protocol for Data Terminal Equipment — Amendment 1

Technologies de l'information — Communication de données — Protocole X.25 de couche paquet pour terminal de données — Amendement 1

General Information

• Status: Withdrawn
• Publication Date: 12-Sep-1990
• Withdrawal Date: 12-Sep-1990
• 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: 27-Jul-1995

Relations

• Amends: ISO/IEC 8208:1990 - Information technology — Data communications — X.25 Packet Layer Protocol for Data Terminal Equipment
• Effective Date: 06-Jun-2022
• Child: ISO/IEC 8208:1990 - Information technology — Data communications — X.25 Packet Layer Protocol for Data Terminal Equipment
• Effective Date: 18-Dec-2008

Standards Content (Sample)

ISOIIEC
INTER NATIONAL
STANDARD
Second edition
1990-03-1 5
AMENDMENT 1
1990-09-1 5
Information technology -
Data communications - X.25 Packet Layer
Protocol for Data Terminal Equipment
AMENDMENT 1 : Alternative Logical Channel
Identifier assignment
Technologies de l'information - Communication de données - Protocole X.25 de
couche paquet pour terminal de données
AMENDEMENT I : Alternative pour l'attribution d'une référence de voie logique
Reference number
ISO/IEC 8208 : 1990/Amd.î : 1990 (E)

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ISO/IEC 8208 : 199WAmd.l : 1990 (E)
Foreword
IS0 (the International Organization for Standardization) and IEC (the International
Electrotechnical Commission) form the specialized system for worldwide standardiz-
ation. 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 information technology, IS0 and IEC have established a joint technical
committee, ISO/IEC JTC 1. 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.
International Standard ISO/IEC 8208/Amd.l was prepared by Joint Technical Com-
mittee ISO/IEC JTC 1, Information technology.
@ ISO/IEC 1990
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.
ISOllEC Copyright Office O Case postale 56 O CH-I211 Genève 20 Y Switzerland
Printed in Switzerland

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ISO/IEC 8208 : 1!390/Amd.l : 1990 (E)
Information technology - Data communications -
X.25 Packet Layer Protocol for Data Terminal Equipment
AMENDMENT 1 :
Alternative Logical Channel Identifier assignment
Page 12
Introduction
International Standard ISO/IEC 8208 : 1990 describes the X.25
Clause 5
Packet Layer Protocol for Data Terminal Equipment. This
First paragraph, add the following: "The procedures for select-
Amendment defines an alternative mechanism for Logical
Channel Identifier assignment. ing a logical channel can be as described here or as described
for the Reference Number Facility.''
The material contained in this Amendment shall be incor-
porated into the body of ISO/IEC 8208 when the next edition is
Page 15
0 published. The text is presented as additions to the text of
ISO/IEC 8208 : 1990.
Subclause 5.2.5
Page 6
Last line, add the following:
Subclause 3.7
"NOTE - When using the alternative Logical Channel Identifier
assignment mechanism (Reference Number Facility), this subclause
Add to the end of this subclause the following: "An alternative
does not apply."
mechanism for Logical Channel Identifier assignment, which
may be used in DTE/DTE environment only, is provided by the
Page 16
Reference Number Optional User Facility. When this
mechanism is used, figure 1 does not apply. Instead, one
Subclause 5.5.4
logical channel exists for each Logical Channel Identifier value
in the range 1 to 4 095, but only a limited number of values -
Add the following immediately under "See also:" "- Optional
as determined by the DTE - need be assigned at any given
User Facility for Reference Number (13.28);"
time to Permanent Virtual Circuits and to Virtual Calls estab-
lished or in the process of being established.
Page 39
"NOTE - The alternative mechanism, by allowing a DTE to
in
choose the logical channel identifier values that can appear
Subclause 12.2.4.2
received packets, can ease the task of managing logical chan-
nels where a DTE can be involved in simultaneous operation First paragraph, delete the secorid sentence and insert the
following: "The extended format ie used for CLEAR CONFIR-
O over multiple DTE/DTE interfaces, a situation typical in LAN
MATION PACKETS issued by a DTE only in conjunction with
environment (e.g. in figure 2, DTE 2 in its communication with
the Reference Number Facility (see 13.281."
DTEs A and BI.
"See also :
Page 73
-
Optional User Facility for Reference Number (13.281."
New subclause 13.28
Page 11
Add the following :
Subclause 4.5
"13.28 Reference Number
First paragraph, add the following: "When using the alter-
native Logical Channel Identifier assignment mechanism
"This optional user facility applies only in a DTE/DTE environ-
(Reference Number Facility), this subclause does not apply."
ment.
"Reference Number is an optional user facility which may be
Page 12
agreed to for a period of time. It applies to a packet layer entity.
It is used as an alternative mechanism for Logical Channel Iden-
Subclause 4.5
tifier assignment. It should be noted that, as this is an optional
Last line, add the following: "- Optional User Facility for facility, the normal mode of operation of a DTE does not make
Reference Number (13.281." use of this facility.
1

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E)
ISO/IEC 8208 : 199WAmd.l : 1990
"When a) applies, the logical channel indicated in the original
"13.28.1 General description
CALL REQUEST d acket's Reference Number Facility may be
"For each Virtual Call or Permanent Virtual Circuit, a pair of returned immediately to state pl, and re-used as necessary.
reference numbers (a Source reference number and a Destina-
"When b) applies, however, the logical channel indicated in the
tion reference number) is assigned to identify the Virtual Call or
originated CALL REQUEST packet's Reference Number Facility
the Permanent Virtual Circuit. For Virtual Calls, these reference
remains assigned to the original call setup attempt, according
numbers are assigned by the two DTEs using the Reference
to the procedures specified in 5.2.1 and, following expiry of
Number Facility during call setup. Reference numbers are in the
timer T21, 5.4 and 15.5.1. Assuming no response is received to
range from 1 through 4 095, inclusive (O shall not be assigned
as a reference number).
"For Virtual Calls the Source reference number is chosen by
the calling DTE when transmitting a CALL REQUEST packet. R23.
The Destination reference number is chosen by the called DTE
"In both situations, the requesting DTE may change its mode
when transmitting a CALL ACCEPTED packet. If the called
of operation and process all subsequent virtual calls without
DTE does not accept the call, no Destination reference number
using the Reference Number Facility.
is chosen.
"See also:
"For a Permanent Virtual Circuit, the reference numbers are
chosen independently by the DTE
...