Hi Debdatta,
I am out of ideas. If you have already web services working in your system then my previous suggestion (activating services in SICF) is probably not going to help.
The time out message is interesting though.
Did you ask the people who provide the service if they are receiving any message ? Maybe they can open a trace and let you know if they are receiving your request. If they do and they have send back a response then at least you know your request has arrived and the problem is with receiving the request.
I am sorry I can't give you much more suggestions. A trace at the servcie provider together with a trace by your basis team at the SAP side might give some more insight in where exactly the error is generated.
