XML Communication Protocols
Purely by definition, it is possible using regular protocols to communicate XML web services over a network. Typically a protocol often used is SOAP. Therefore, a client can communicate with a XML Web service using specific SOAP messages, these can encapsulate other parameters such as XML. This is certainly useful, especially because for the XML Clients, there is a proxy class which allows parameters to be mapped directly to XML elements – which are then contained and distributed using the SOAP messages.
The crucial component is the service description. It is essential that this description matches the Web Services Description Language Specifications (WSDL). This service description is essential for communication because it defines how any client must communicate with the XML web service application. It is within this service description that you can define specific clases, for example where there is a strong requirement for perhaps internet anonymity then you could specify a proxy class within the WSDL.
After this has been specified the Web service client can then use the various components of the proxy. The proxy could then commounicate with the XML web service directly including processing all the SOAP messages but at the same time maintaining the anonymity of the client’s IP address. It is important that because this can be used across the internet a trusted destination should be referenced with the proxy class itself. The default setting on Microsoft implementations is to use SOAP over HTTP to communicate. The WSDL though is able to generate specific proxy classes that can communicate using both HTTP transfer requests of GET and POST. This is invoked by simply adding a protocol switch to select either a POST or GET request being issued.