Do not do any "polling" like the other poster said to you. It's completely wrong.
You need to write a client server program and verify that the local router supports multicasting and is multicasting enabled.
Do this from your server program:
Create a multicasting group from within your server application (a predecided IP, amongst the available multicasting IP slots). Now the server application simply sends packets to this IP address continuously, as and when required.
Do this from your client program:
Join the said multicasting group and listen on the preagreed port. All the peers that have joined the group will be automatically notified by the router with the packets sent to the multicasting group.
What I described would apply for
local level (LAN). For taking this on the web, you'll need to be connected to the
MBone[
^] first and then proceed from there. (Explaining the architecture of MBone or Multicasting itself is out of scope of this thread).
Important: If you have further queries or doubts, click on the "New Message" at the bottom of this page to provide more clarification.