How to know client system has disconnected network cable in WCF using callback?

I 开发者_如何学Goam developing one WCF server where i am using netTcp & dualWsHTTP binding. I have a scenario where the client instantly pull the network cable, so in this case how WCF server will know the client is no more

This is fundamentally impossible. With TCP/IP, the connection doesn't break when the network cable is pulled. It doesn't break until one side realizes that the other side is gone, which will usually happen when sending data. If the server isn't sending data, it won't notice the client isn't there.