WS-A Issue 27 - Reference to WSDL definition in an EPR

ISSUE 27 - Reference to WSDL definition in an EPR
  According to the ws-addressing submission, "Endpoint references convey the information needed to identify/reference a Web service endpoint, and may be used in several different ways: endpoint references are suitable for conveying the information needed to access a Web service endpoint...."  However, in order to assure that the information needed to access a Web service endpoint, a reference to the WSDL definition of a service is sometimes required and in those cases must be included as part of the EPR construct.
 
This requirement derives from several common use cases. For example, in a communication chain there may be intermediaries that can accept incoming messages and, in a fully dynamic manner, further dispatch or route those onward. This is what we do with our products.  The trick is that the next recipient might use a completely different protocol/transport/format than what the message came in on. For this case it is necessary to perform a fully dynamic dispatch by using the target's WSDL definition and to build dynamic proxies and to bind to the service over one of the protocol/transport/format combinations it supports. The whole definition is required so there is access to all the possible bindings for the service. The WSDL definition is also used in cases where consumer applications want to avoid compiling in static port type information, and instead want, for flexibility purposes, late (runtime) binding to the service.