(WMB) SOAP Vs HTTP Nodes

This post talks about the preferences of using one type of nodes over others. During the course of my experience in using these nodes, I had several confusions regarding when to use what & what is the main difference among these nodes.


We can use SOAP nodes with SOAP message domain OR HTTP transport nodes with XMLNSC message domain to implement Web Services. Several advantages exist if we use SOAP nodes :

• Support for WS-Addressing, WS-Security and SOAP headers.
• A common SOAP logical tree format, independent of the bitstream format.
• Runtime checking against WSDL.
• Automatic processing of SOAP with Attachments (SwA). (Although the HTTP nodes can process SwA messages, we must use the MIME message domain)
• Automatic processing of Message Transmission Optimization Mechanism (MTOM).

Cases where it might be better to use HTTP nodes include:

• Message flows that interact with Web services that use different standards, such as REST or XML-RPC. (We don't have a WSDL definition)
• Message flow that never use WS-Addressing, WS-Security, SwA, or MTOM.

MTOM :

• It is the W3C Message Transmission Optimization Mechanism, a method of efficiently sending binary data to and from Web services.
• The efficiency claims of MTOM only refers to the size of the messages sent across the wire. 
• Since SOAP uses XML, any binary data in the SOAP message will have to be encoded as text. This is usually done using Base64 encoding which increases the size of the binary data by 33%. 
• MTOM provides a way to send the binary data in its original binary form, avoiding any increase in size due to encoding it in text. 
• MTOM does not address the efficiency of serializing or deserializing the messages.