Networking Services (XNS) Issue 5
Copyright © 1997 The Open Group

Frontmatter


CAE Specification
Networking Services (XNS) Issue 5
X/Open Document Number: C523
ISBN: 1-85912-165-9


©February 1997, The Open Group All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owners.


Portions of this document are extracted from IEEE Std 1003.1-1990, copyright © 1990 by the Institute of Electrical and Electronics Engineers, Inc. with the permission of the IEEE.

Portions of this document were extracted from IEEE Draft Standard P1003.2/D12, copyright © 1992 by the Institute of Electrical and Electronics Engineers, Inc. with the permission of the IEEE. No further reproduction of this material is permitted without the written permission of the publisher. IEEE Std 1003.2-1992, copyright © 1992 by the Institute of Electrical and Electronics Engineers, Inc., and ISO/IEC 9945-2:1993, Information Technology - Portable Operating System (POSIX) - Part 2: Shell and Utilities, are technically identical to IEEE Draft Standard P1003.2/D12 in these areas.

Portions of this document are derived from copyrighted material owned by Hewlett-Packard Company, International Business Machines Corporation, Novell Inc., The Open Software Foundation, and Sun Microsystems, Inc.


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Preface

The Open Group

The Open Group is the leading vendor-neutral, international consortium for buyers and suppliers of technology. Its mission is to cause the development of a viable global information infrastructure that is ubiquitous, trusted, reliable, and as easy-to-use as the telephone. The essential functionality embedded in this infrastructure is what we term the IT DialTone. The Open Group creates an environment where all elements involved in technology development can cooperate to deliver less costly and more flexible IT solutions.

Formed in 1996 by the merger of the X/Open Company Ltd. (founded in 1984) and the Open Software Foundation (founded in 1988), The Open Group is supported by most of the world's largest user organizations, information systems vendors, and software suppliers. By combining the strengths of open systems specifications and a proven branding scheme with collaborative technology development and advanced research, The Open Group is well positioned to meet its new mission, as well as to assist user organizations, vendors, and suppliers in the development and implementation of products supporting the adoption and proliferation of systems which conform to standard specifications.

With more than 200 member companies, The Open Group helps the IT industry to advance technologically while managing the change caused by innovation. It does this by:

The Open Group operates in all phases of the open systems technology lifecycle including innovation, market adoption, product development, and proliferation. Presently, it focuses on seven strategic areas: open systems application platform development, architecture, distributed systems management, interoperability, distributed computing environment, security, and the information superhighway. The Open Group is also responsible for the management of the UNIX trademark on behalf of the industry.

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This Document
This document is a CAE Specification, although it includes some appendices which are classed as Preliminary Specifications. The introductory section in each appendix clearly identifies its status.

The Networking Services (XNS) specification describes the industry-standard Open Systems interfaces to communications services. These include two APIs to transport-level process-to-process communications: Sockets and XTI. Both Sockets and XTI are specified for use over Internet protocols (TCP, UDP and IP) and ISO Transport protocols. They also include a set of Internet address resolution interfaces which are commonly used in conjunction with Sockets. XTI support for many other protocols is described in appendices to XNS.

This XNS Issue 5 is one of the UNIX98 specifications. Branded UNIX98 systems support the Sockets, XTI and Address Resolution interfaces described in XNS Issue 5. Sockets and Address Resolution must be supported over the Internet protocols. XTI may be supported over either the Internet or ISO Transport protocols. Other protocols may also be provided, but this is not required for the Brand.

XNS Issue 5 contains a number of new features over the previous publication1. The most important new feature is the removal of implicit data length assumptions (for example, that an item of type int is 32 bits long). This enables the XNS APIs to be used effectively on new computer architectures with 64-bit (or larger) word lengths. Other new features include:

XNS Issue 5 includes revisions to align with the IEEE Standard 1003.1: 1990 (Portable Operating System Interface). At the time of publication, the IEEE project P1003.1g is considering draft extensions, and their current draft includes some aspects with which XNS can not align (for example, it still makes implicit data length assumptions). Attempts are being made in P1003.1g to seek alignment with XNS Issue 5.

Structure
Typographical Conventions
The following typographical conventions are used throughout this document:

Trade Marks

AT&T® is a registered trademark of AT&T in the U.S.A. and other countries.

Hewlett-PackardTM; is a trademark and HP® is a registered trademark of Hewlett-Packard Company.

Motif®, OSF/1®, and UNIX® are registered trademarks and the IT DialToneTM;, The Open GroupTM;, and the "X Device"TM; are trademarks of The Open Group.

SNA is a product of International Business Machines Corporation.

/usr/group® is a registered trademark of UniForum, the International Network of UNIX System Users.

Acknowledgements

Referenced Documents

The following documents are referenced in this specification:
ACSE

ISO 8649

ISO 8649:1988, Information Processing Systems - Open Systems Interconnection - Service Definition for the Association Control Service Element, together with:
Technical Corrigendum 1:1990 to ISO 8649:1988 Amendment 1:1990 to ISO 8649:1988 Authentication during association establishment. Amendment 2:1991 to ISO 8649:1988 Connectionless-mode ACSE Service.

ISO 8650

ISO 8650:1988, Information Processing Systems - Open Systems Interconnection - Protocol specification for the Association Control Service Element, together with:
Technical Corrigendum 1:1990 to ISO 8650:1988 Amendment 1:1990 to ISO 8650:1988 Authentication during association establishment.

ISO/IEC 10035

ISO/IEC 10035:1991, Information Technology - Open Systems Interconnection - Connectionless ACSE Protocol Specification.

Presentation

ISO 8822

ISO 8822:1988, Information Processing Systems - Open Systems Interconnection - Connection-oriented Presentation Service Definition.

ISO 8823

ISO 8823:1988, Information Processing Systems - Open Systems Interconnection - Connection-oriented Presentation Protocol Specification.

ISO 8824

ISO 8824:1990, Information Technology - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1).

BER

ISO/IEC 8825:1990 (ITU-T Recommendation X.209 (1988)), Information Technology - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1).

ISO/IEC 9576

ISO/IEC 9576:1991, Information Technology - Open Systems Interconnection - Connectionless Presentation Protocol Specification.

Session

ISO 8326

ISO 8326:1987, Information Processing Systems - Open Systems Interconnection - Basic Connection-oriented Session Service Definition.

ISO 8327

ISO 8327:1987, Information Processing Systems - Open Systems Interconnection - Basic Connection-oriented Session Protocol Specification.

Amendment 3:1992 to ISO 8327:1987 - Additional Synchronization Functionality.

ATM

ATMNAS
ATM Forum: "Native ATM services: Semantic Description, Version 1", obtainable via anonymous ftp from Internet address ftp.atmforum.com, in directory /pub/approved-specs, files af-saa-0048.000.doc (Word 6.0) or af-saa-0048.000.ps (postscript).

UNI
ATM Forum: "ATM User-Network Interface (UNI) Specification, Version 3.1", published by Prentice Hall. Also obtainable electronically via anonymous ftp from Internet address ftp.atmforum.com, in directory /pub/UNI/ver3.1.

Other References

Minimal OSI

ISO/IEC DISP 11188-3, International Standardized Profile - Common Upper Layer Requirements - Part 3: Minimal OSI Upper Layers Facilities, Version 6, 1994-04-14.

ISO 7498

ISO 7498:1984, Information Processing Systems - Open Systems Interconnection - Basic Reference Model.

ISO Transport

    Connection-Oriented
Protocol Definition IS 8073-1986 IS 8602
Service Definition IS 8072-1986 IS 8072/Add.1-1986

TCP

Transmission Control Protocol, RFC 793 (Defense Communication Agency, DDN Protocol Handbook, Volume II, DARPA Internet Protocols, (December 1985).

Also see TCP, Transmission Control Protocol, Military Standard, Mil-std-1778, Defense Communication Agency, DDN Protocol Handbook, Volume I, DOD Military Standard Protocols (December 1985).

UDP

User Datagram Protocol, RFC 768 (Defense Communication Agency, DDN Protocol Handbook, Volume II, DARPA Internet Protocols, December 1985).

TLI Specifications

Networking Services Extension, draft version of SVID Issue 2, Volume III, 1986.

NetBIOS

Mappings of NetBIOS services to OSI and IPS transport protocols are provided in the CAE Specification, October 1992, Protocols for PC Interworking: SMB, Version 2 (ISBN: 1-872630-45-6, C209).

SNA

SNA National Registry, IBM document G325-6025-0.

CURL

Common Upper Layer Requirements, Part 3: Minimal OSI Upper Layer Facilities - OIW/EWOS working document.

XSH, Issue 5

CAE Specification, January 1997, System Interfaces and Headers, Issue 5 (ISBN: 1-85912-181-0, C606).

XCU, Issue 5

CAE Specification, January 1997, Commands and Utilities, Issue 5 (ISBN: 1-85912-191-8, C604).

XBD, Issue 5

CAE Specification, January 1997, System Interface Definitions, Issue 5 (ISBN: 1-85912-186-1, C605).


Footnotes

1.
The previous XNS publication was CAE Specification, September 1994, Networking Services, Issue 4, (ISBN: 1-85912-049-0, C438).


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