ucture (struct). A SOAP request struct has the same name and type as the method/procedure being invoked. It should be noted that XML-RPC and SOAP are not the same and have a separate specification associ- ated with use of RPC in XML. The XML-RPC has specifications for basic request- response RPC in XML with HTTP as transport, while SOAP is a more enhanced version of XML-RPC having user-defined data types, the ability to specify the destination node, message specific processing, and other features that are absent in XML-RPC. When a SOAP message is received at the destination node the message is pro- cessed. The processing would involve parsing the message, checking if the message is syntactically correct and identify the action to be performed. Intermediate nodes (nodes between source and destination nodes in a message path) can be added to the message path without changing the parsing and associated message processing logic. Even removing the header, changing the header, reinserting the header, or adding a new header can be performed. There are two types of intermediaries in SOAP. They are the forwarding inter- mediaries and active intermediaries. Forward intermediary performs the basic capability of forwarding the SOAP message to another SOAP node that can be another intermediary or the final destination node. The actions performed by XML-Based Protocols forwarding intermediary is limited to removing of header blocks that are pro- cessed and that which cannot be relayed. Active intermediary performs additional processing that involves modifying the SOAP message before the basic forwarding action. This processing can be related to content manipulation or security related service offering. This additional processing performed by an active SOAP inter- mediary should be marked by inserting a header block to ensure that the changes are detectable by other nodes downstream, which includes intermediaries and the final destination node. SOAP infoset should be serialized and concrete to ensure proper transmission and rec