Opening a channel is a separate step from sending a message, like the handshaking before face-to-face conversations, or that of synchronous communication.

The system supported synchronous communications at up to 9600 baud, and usually served as a remote job entry system to a larger mainframe computer.

Standard routines for synchronous communication such as send and receive were available as well as asynchronous system calls.

The communication matrix establishes a protocol for synchronous communication.

The T2000 added support for synchronous communications, typically used between mainframe computers.

On the other hand, people prefer synchronous communication like IM for immediate good news.

Speech act profiling has been used to detect deception in synchronous computer-mediated communication.

Similar functionalities can be defined for broadcast communication, or synchronous communication.

Pi calculus is based upon synchronous (hand-shake) communication.

A face-to-face discussion is an example of synchronous communications.