The SOAP message path

The SOAP message path is the set of SOAP nodes through which a single SOAP message passes. This includes the initial SOAP sender, zero or more SOAP intermediaries, and an ultimate SOAP receiver

In the simplest case, a SOAP message is transmitted between two nodes, that is from a SOAP sender to a SOAP receiver. However, in more complex cases, messages can be processed by SOAP intermediary nodes, which receive a SOAP message, and then send it to the next node. Figure 1 shows an example of a SOAP message path, in which a SOAP message is transmitted from the initial SOAP sender node, to the ultimate SOAP receiver node, passing through two SOAP intermediary nodes on its route.
Figure 1. An example of a SOAP message pathA SOAP message path, consisting of an initial SOAP node, two SOAP intermediary nodes, and an ultimate SOAP node

A SOAP intermediary is both a SOAP receiver and a SOAP sender. It can (and in some cases must) process the header blocks in the SOAP message, and it forwards the SOAP message towards its ultimate receiver.

The ultimate SOAP receiver is the final destination of a SOAP message. As well as processing the header blocks, it is responsible for processing the SOAP body. In some circumstances, a SOAP message might not reach an ultimate SOAP receiver, for example because of a problem at a SOAP intermediary.