The Application Server role installation process provides an option for turning on TCP Port Sharing. The Net.Tcp Port Sharing service, a new system component that is part of Windows Communication Foundation (WCF), enables TCP Port Sharing.

Applications can use TCP to communicate over public and private networks. Many applications on a single computer can use TCP for communication. The TCP/IP protocol uses a 16-bit number, called a port, to differentiate connections to multiple network applications that run on the same computer. If an application is listening on a port, all TCP traffic for that port goes to that application. Other applications cannot listen on that port at the same time.

Net.Tcp Port Sharing facilitates the sharing of TCP ports across multiple processes that use WCF for communication. When a WCF service that uses net.tcp:// port sharing opens, the WCF TCP transport infrastructure does not directly open a TCP socket in the application process. Instead, the transport infrastructure registers the service’s base address Uniform Resource Identifier (URI) with the Net.Tcp Port Sharing Service and waits for the port sharing service to listen for messages on its behalf. Messages that are addressed to the application service are dispatched by the port sharing service as they arrive.

Net.Tcp Port Sharing is transparent to remote applications that send messages. There is no need to make remote applications aware that Net.TCP Port Sharing is enabled.

As a security precaution, the Net.Tcp Port Sharing service is not enabled by default. To enable this service, select the TCP Port Sharing check box on the Select Role Services page during Application Server installation.