Network Working Group M. Rose
Request for Comments: 3340 Dover Beach Consulting, Inc.
Category: Standards Track G. Klyne
Clearswift Corporation
D. Crocker
Brandenburg InternetWorking
July 2002
The Application Exchange Core
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract
This memo describes Application Exchange (APEX) Core, an extensible,
asynchronous message relaying service for application layer programs.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Architecture at a Glance . . . . . . . . . . . . . . . . . 4
2. Service Principles . . . . . . . . . . . . . . . . . . . . 5
2.1 Modes of Operation . . . . . . . . . . . . . . . . . . . . 5
2.2 Naming of Entities . . . . . . . . . . . . . . . . . . . . 6
2.2.1 Comparing Endpoints . . . . . . . . . . . . . . . . . . . 7
3. Service Provisioning . . . . . . . . . . . . . . . . . . . 7
3.1 Connection Establishment . . . . . . . . . . . . . . . . . 7
3.2 Authentication . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Authorization . . . . . . . . . . . . . . . . . . . . . . 8
3.4 Confidentiality . . . . . . . . . . . . . . . . . . . . . 8
3.5 Relaying Integrity . . . . . . . . . . . . . . . . . . . . 8
3.6 Traffic Analysis . . . . . . . . . . . . . . . . . . . . . 9
4. The APEX . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Use of XML and MIME . . . . . . . . . . . . . . . . . . . 9
4.2 Profile Identification and Initialization . . . . . . . . 10
4.3 Message Syntax . . . . . . . . . . . . . . . . . . . . . . 11
Rose, et. al. Standards Track [Page 1]
RFC 3340 The Application Exchange Core July 2002
4.4 Message Semantics . . . . . . . . . . . . . . . . . . . . 11
4.4.1 The Attach Operation . . . . . . . . . . . . . . . . . . . 11
4.4.2 The Bind Operation . . . . . . . . . . . . . . . . . . . . 13
4.4.3 The Terminate Operation . . . . . . . . . . . . . . . . . 14
4.4.4 The Data Operation . . . . . . . . . . . . . . . . . . . . 15
4.4.4.1 Relay Processing of Data . . . . . . . . . . . . . . . . . 17
4.4.4.2 Application Processing of Data . . . . . . . . . . . . . . 18
4.5 APEX Access Policies . . . . . . . . . . . . . . . . . . . 19
4.5.1 Access Policies in the Endpoint-Relay Mode . . . . . . . . 19
4.5.2 Access Policies in the Relay-Relay Mode . . . . . . . . . 20
5. APEX Options . . . . . . . . . . . . . . . . . . . . . . . 20
5.1 The statusRequest Option . . . . . . . . . . . . . . . . . 22
6. APEX Services . . . . . . . . . . . . . . . . . . . . . . 26
6.1 Use of the APEX Core DTD . . . . . . . . . . . . . . . . . 27
6.1.1 Transaction-Identifiers . . . . . . . . . . . . . . . . . 27
6.1.2 The Reply Element . . . . . . . . . . . . . . . . . . . . 28
6.2 The Report Service . . . . . . . . . . . . . . . . . . . . 28
7. Registration Templates . . . . . . . . . . . . . . . . . . 29
7.1 APEX Option Registration Template . . . . . . . . . . . . 29
7.2 APEX Service Registration Template . . . . . . . . . . . . 29
7.3 APEX Endpoint Application Registration Template . . . . . 30
8. Initial Registrations . . . . . . . . . . . . . . . . . . 30
8.1 Registration: The APEX Profile . . . . . . . . . . . . . . 30
8.2 Registration: The System (Well-Known) TCP port number for
apex-mesh . . . . . . . . . . . . . . . . . . . . . . . . 31
8.3 Registration: The System (Well-Known) TCP port number for
apex-edge . . . . . . . . . . . . . . . . . . . . . . . . 31
8.4 Registration: The statusRequest Option . . . . . . . . . . 31
8.5 Registration: The Report Service . . . . . . . . . . . . . 32
9. DTDs . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
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