As such a query is a two stage process, I would imagine it would go
something like this:
1. Client makes request with MSISDN and return URL
2. Server posts result (as HTTP GET or POST) back to client as soon as
the necessary information is received back from the remote operator.
As this is such a simple thing, I don't believe it's necessary to wrap
it all up in SOAP - a simple HTTP request should do.
I think the protocol you use will be dependent somewhat on the
average length of time for the lookup. There is more overhead in
having to have 2 connection setups (1 outbound and 1 inbound) than in
just the one. But it probably comes down to volumes as well, and if
the calling application minds blocking for an answer.
I think you should consider making it optional to offer a callback
URL, or to wait for a response. Suggest you support SSL as well.
If I were to wrap it up in anything I would personally go for XML-RPC
as its somewhat simpler than SOAP.
Regards
Ben
