Synchronous Data Link Control networks

Synchronous Data Link Control (SDLC) is a protocol that is used for transferring synchronous, code-transparent, serial-by-bit information over a communications line.

Transmission exchanges can be duplex or half-duplex over switched or nonswitched lines. The configuration of the connection can be point-to-point, multipoint, or loop.

SDLC has the following meanings:

A form of communications line control that uses commands to control the transfer of data over a communications line.
A communications discipline that conforms to subsets of the Advanced Data Communication Control Procedures (ADCCP) of the American National Standards Institute (ANSI) and high-level data link control (HDLC). These standards are part of the International Organization of Standardization.

Note: SDLC supports traditional iSeries communication protocols, such as APPC, but does not support TCP/IP.