The Web Service Addressing protocol is used to select certain service
and port on a SOAP server, just like the "Host" header in "HTTP".

The basic SOAP design uses the URI and the "soapAction" header of HTTP
(in case it uses HTTP, by far the most often used transport mechanism)
However, when the server is hidden behind firewalls and proxies, these
fields are rewritten or replaced.  This means that the definitions by
the WSDL for the client can differ from the configuration of the

WWW: http://search.cpan.org/dist/XML-Compile-SOAP-WSA/