Related Transports

Two fragmentary transport definitions are called related transports when they cooperate to establish a bus.

For example, dynamic TCP transport definitions are related when they define a listen end and a connect end within the same transport group. Other connection-oriented transport definitions are related when they define a listen end and a connect end on the same port number. Asymmetric multicast transport definitions are related by the send and listen groups they share.

Note: Administrators must properly configure related transports so that they can establish a bus. As a counterexample, consider a static TCP transport, T1, which listens on port 5678, and a static TCP transport, T2, which connects on port 7890. These transports are not related, and cannot establish a TCP connection.

When related transports establish a bus, data flows between them through the bus. The following diagram depicts two program processes, each with one endpoint. A pair of related transports implements the two endpoints. Curved arrows on the right show the data flow among the abilities of the related transports. Notice that when process P1 sends a one-to-one message, it flows through the send inbox ability over transport T1, then into process P2 through the receive inbox ability of transport T2 and P2 receives it in its inbox (which instantiates endpoint E2).

Related Transports: Data Flow