File Objects Represent Connection Endpoints
A file object that represents an open connection endpoint identifies a specific connection on which local and remote-node peer processes are communicating with each other across the network or will communicate with each other when the local-node process has established an endpoint-to-endpoint connection with a remote-node peer.
Any such file object must be associated with another open file object that represents a particular transport address. The transport address identifies the process, as already described in File Objects Represent Transport Addresses.
In a similar manner, the transport uses the file object representing the local connection endpoint to maintain state about the remote-node peer process, such as the remote-node transport address, with which its local-node client establishes an endpoint-to-endpoint connection.
A client process can establish many endpoint-to-endpoint connections between itself and other processes on remote nodes. For example, the redirector establishes separate connections between itself and each remote server for Windows 2000 and later with which it communicates. Such a client can have several open connection endpoints all separately associated with an open transport address.
A process cannot send data over an endpoint-to-endpoint connection unless it has a means of identifying which of all existing connections the data is to be sent over. Each open file object that represents a connection endpoint is used to discriminate among established endpoint-to-endpoint connections of the same process.
Note The TDI feature is deprecated and will be removed in future versions of Microsoft Windows. Depending on how you use TDI, use either the Winsock Kernel (WSK) or Windows Filtering Platform (WFP). For more information about WFP and WSK, see Windows Filtering Platform and Winsock Kernel. For a Windows Core Networking blog entry about WSK and TDI, see Introduction to Winsock Kernel (WSK).