Early SOAP implementations varied in their interpretations of this part of the SOAP specification, causing some rather nasty and annoying integration problems (ironic because SOAP's main goal is to enable interoperability). In particular, the IBM (later Apache) SOAP implementation chose the route of requiring xsi:type based typing (forgoing the other two options completely) while the Microsoft SOAP implementation chose to completely ignore the xsi:type option in favor of using schemas based on an external service description document.

NET allows the operations to be invoked one of three different ways: through an HTTP-GET operation, through an HTTP-POST operation, or through the use of SOAP messages. NET is one of the only web services platforms that allow web services to be invoked using multiple protocols. asmx file to a location in your IIS web root. asmx file's URL. For example, if your Microsoft IIS server is installed at c:\inetpub (the default installation location), the web root is c:\inetpub\wwwroot. asmx, where localhost is the DNS name or IP address of your IIS server.