c# - notify client from server -

if have asp.net application, , want notify user when changes on server, how do this. same thing silverlight client. silverlight client there form of subscribing event on server silverlight client?

there 2 ways. first 1 check server every few minutes, believe not search obvious way, search technique called comet.

comet technique creates , opens connection server client, , when server closes connection, means there new message client, client reads messages, , opens new connection waiting next message. other way open connection , stream data, when available server client, , not close connection @ all. thing need take care of increase number of open connections allowed site.

check sites comet asp.net

http://www.frozenmountain.com/websync/

or

http://www.aaronlerch.com/blog/2007/07/08/creating-comet-applications-with-aspnet/