Service based applications changed the development practices. Service oriented architecture provided a new way to look at the application development and took it one step ahead in development world.
Web service and Simple Object Access Protocol (SOAP) has made data transmission between different applications very easy without worrying about underlying architecture and platform detail. SOAP architecture provides good platform for secured data transmission over HTTP with that said, if you have to develop an application that is going to run over TCP then you would have to determine and develop application that is going to support that kind of network.
Windows Communication Foundation (WCF) supports various protocols like TCP/IP, HTTP and even Peer networking using mesh network topology. In other words, WCF contains everything that modern service oriented application need. [More]