Possible connectivity issues

[Sky Fly]

Hi,

I have installed a .NET application that calls
a webservice method. The method takes a array
of bytes (which is created by deserialising a file)
as an argument and processes this. Afterwards,
the file that the array of bytes was created from
is deleted.

I'm finding that the application is calling the
method, but nothing seems to be happening - the
process never gets to the stage where the file is
deleted. So I'm trying to find out what might
be the problem.

One thing I need to be sure of is what exactly
happens when a web method is called by a client -
is it that the parameters have to be transmitted
across to the web service first, and only then
can the web method begin to execute? If this is
the case, will intermittent loss in connectivity
from the client to the web service cause the
web method call to start all over again? Is
there any other thing that might cause a call
to a web method to hang?

TIA,