WCF duplex communication

Question

Is duplex communication is possible in WCF?

Answer 1

It surely is. If you want more information, go to the WCF section of MSDN.

Answer 2

I have a duplex proxy tunnel that I wrote that works over WCF. Feel free to check it out as an example.

Answer 3

Duplex mode communication means two way communication. Normally in WCF the client calls the server. But there is no way for the server to call the client, e.g. to notify a chat client that there is a new chat message available.

With a duplex contract the server provides an interface that the client has to implement. Now there are two interfaces one that the server implements as usual and one that the client implements. This enables the server to call methods on the client. In a chat program scenario this enables the server to notify the client when a new message is available, instead of the client having to constantly check with the server if there is something new.