WS-Addressing is useful in situations where the SOAP response can’t be served immediately. Either the resources to form the response are not available right away or the result itself takes a long time to be generated. There are times where your business takes time.something which needs manually intervention, something to be approved, whatever, but it takes days to do it. keeping the connection opened all that time and waiting for the response would be inefficient.notification process comes to rescue in these kind of scenarios.The client makes a requests but does not wait for the response. It instead instructs the server where to send the response by use of a “reply to” address. Once the response is available, the server connects to that address and sends the response.Instead of relying on network-level transport to convey routing information, a message utilizing WS-Addressing may contain its own dispatch metadata in a standardized SOAP header.WS-Addressing you are not tied to that. You can demand the response on another type of channel. Request comes on HTTP for example, but you can instruct the server to send the response back over SMTP, for example.