FW: Proposed draft text for 2.2.21

[Forwarding to public list ... anyway, it doesn't seem to be in the admin
list archives!]

-----Original Message-----
From: Hao He [mailto:Hao.He@thomson.com.au]
Sent: Thursday, June 26, 2003 9:24 AM
To: 'Champion, Mike '; 'w3c-ws-arch@w3.org '
Subject: Proposed draft text for 2.2.21




 
2.2.21.1 Summary

A message is the basic unit of data sent from one software agent to another
during an interaction of Web services. The architecture defines an
interaction as a software agent sending a request message to a service and
receiving zero or more response messages. 

2.2.21.2 Relationships to other elements

a message is
a unit of data sent from one agent to another

a message may be part of
a message exchange pattern

a message may be described using
a message description language

a message has
a message sender

a message has
zero or more message recipients

a message may have
a message identifier

a message may have
a message content

a message may have
zero or more message headers

a message may have
a message envelope

an interaction has
a request message

an interaction has
zero or more response message

Description

A message represents the data structure passed to a service during its
request, and received from a service during its response (if any). The
structure of request and responses (if any) are defined in service
descriptions.  In a synchronous

interaction, the request message and the response message (if any) are
implicitly related. In an asynchronous interaction, the request message and
the response messages (if any) must be explicitly related.

A message is defined as a construct that can include zero or more headers,
an envelope, data within the envelope and data external to the envelope. The
header part of a message can include information pertinent to extended Web
services functionality, such as security, transaction context, orchestration
information, message routing information, or management information. The
data part of a message contains the message content or URIs to the actual
data.

A message can be as simple as an HTTP GET request, in which the HTTP headers
are the headers and the parameters encoded in the URL are the content.

A message can also simply be a plain XML.  However, such messages do not
support extended Web services functionality defined in this architecture.

A message can be a SOAP XML, in which the SOAP headers are the headers.
Extended Web services functionality are supported in SOAP headers.