Building a client/server application with system.net.sockets throught client firewall and router

I'm making a client/server application, the application has a server application that will be located on a remote host, and a client application that could be located on different client with different IP address. The server application will have his ip address on port 80, and it will listen the different client request. This client/server application will support also a real time chat, so......., if the different client are behind firewall and router, could the serv开发者_StackOverflower send real time messages to the clients application throught these firewall and router, and then waiting for them response too.

If the ports are open...yes.

One common way around this is to park a request on the server, and then respond to that. Most firewalls aren't going to allow you to make a request to the client. So, you make an asynchronous request to the server, and the server doesn't return until there is something meaningful to send to the client. Then, after the response is sent, have the client park another request for the next piece(s) of server data.