To do this the client would need to be listening on a port or something. In
my opinion it's not good practise. If your client can't reach your server
then the user can't use the app, by doing this you introduce the additional
problem that if the server can't reach the client then the app will only
work partially. It's very common in work environments that an Internet
server cannot reach the client because the client is likely to be behind
firewalls etc.
You should consider a different approach, such as
01: Client posts request
02: Server returns a job number
03: Client occasionally polls the server with the job number to check
progress
--
Pete
====
http://mrpmorris.blogspot.com
http://www.capableobjects.com - Think domain, not database