Which MEP is right for you?
The methods by which SOAP messages can pass back and forth are called Message Exchange Pattern. MEPs are three types. However they get up to six types based on whether order of message received is important. I'll explain:
Datagram - During a datagram MEP a client sends a message using a fire and forget exchange, exchange that requires out-of-band confirmation
of successful delivery. All it cares about is successfully sending the message and does not guarantee that the remote endpoint has received
Request-Response - This type of MEP is more courteous: a message is sent, and a reply is received. Remote procedure calls (RPC) and browser GET requests use this type of MEP.
Duplex - This type of MEP allows an arbitrary number of messages to be sent by a client and received in any order.
The most widely used pattern is, however, the Publisher-Subscriber pattern where a message broadcasted by a publisher is listened by the subscriber clients. Subscribers has to send requests to get a copy of the message. Publisher-Subscriber pattern will be used to build secure messaging capacities for the gateways in the power cower grid control systems.