Alot has been said about the request response scenario in BizTalk. I’m afraid this topic is still in confusion amongst BizTalk developers in general, and while understanding the capabilities of BizTalk’s ESB toolkit.
The ESB toolkit 2.0/2.1 allows sending message to destination system and correlating a response on it. This is acheived by the Enterprise application block (Caching) behind the scenes. The itinerary header for the initial send is cached, and respective correlation information (TransmitID) is stored in the Application block. Upon receiving response, it is correlated on the same token, the itinerary header is retreived from the Cache manager and then attached to the message.
I’ve elaborated the whole working with two pictures. They carry a a lot of detail – but worth the effort!
Happy coding 🙂