SOAP

Background

From the draft W3C specification: “SOAP is a lightweight protocol for exchange of information in a decentralized, distributed environment. It is an XML based communication protocol that consists of three parts:

• An envelope that defines a framework for describing what is in a message and how to process it;

• A set of encoding rules for expressing instances of application-defined data types; and

• A convention for representing remote procedure calls and responses.

Web Services Description Language (WSDL) is a specification defining how to describe Web Services in a common XML grammar. It describes four critical pieces of data:

• Interface information describing all publicly available functions

• Data type information for all message requests and message responses

• Binding information about the transport protocol to be used

• Address information for locating the specified service

WSDL is platform and language-independent and is used primarily (although not exclusively) to describe SOAP services. Using WSDL, a client can locate a web service and invoke any of its publicly available functions. With WSDL-aware tools (such as .NET), you can automate this process, enabling applications to easily integrate new services with little or no manual code.

Definitions, Acronyms and Abbreviations

This document uses the following definitions, acronyms and abbreviations.

Acronym	Definition
SOAP	Simple Object Access Protocol
XML	Extended Mark-up Language
WSDL	[Services Description Language]

Soap Interface Purpose

The SOAP interface to NADS is intended for communicating and responding to requests from a client application. As such the format is designed with machine readability rather than human readability in mind.

The SOAP interface has two major roles:

1. Receipt and processing of incoming SOAP requests that describe new jobs to be created and dispatched.
2. Generation and sending of responses to requests detailing job progress/status information to the originator of the job.

Encoding

Messages in this document are written to conform to the SOAP specification as registered at [1]. More specifically, the internal structure of the messages match the WSDL describing the exact message structure used in relation to the NADS SOAP interface.