Rob,

Thanks for the reply.
There is one more interesting thing happened during the connection closed
scenario, the web servicce actually DID the work , even though from the
client side, it report a WebException, I guess it is because the
communication is severed, that's why I said retry did not work well. Just
FYI.

I agree with you , after googled two days, my final decision is do nothing,
there is no way to prevent this kind of scenario from happening, in our
production environment, it allows retry, as long as conneciton closed is not
happening too frequently,we are fine. Also, I tend to give the challenge to
our system engineer group to resolve the mystry of who close the connection.
For application, we have done the max we can.

Mike