Secure XML: The New Syntax for Signatures and Encryption

8.4. SOAP Transport Binding and HTTP

To actually get SOAP messages from one node to another, you must use some underlying transport protocol, such as HTTP [RFC 2616] or SMTP [RFC 2821, 2822]. The extent to which you must augment or restrict the transport protocol varies depending on how closely the native mechanism of the protocol matches the needs of SOAP.

By convention, most TCP/IP-based protocols have a default “port” number—for example, port 80 for HTTP and port 25 for SMTP. Servers that support a protocol normally have, listening on the default port, a process that handles incoming service requests. The SOAP specification recommends the use of a different port number when you use an existing transport protocol with SOAP. This recommendation ...