Online Computer Terms Dictionary - X

X.25

<protocol, standard> An ITU-T standard protocol suite for the DTE-DCE interface in a packet-switched network, approved by ISO. X.25 defines standard physical layer, data link layer and network layers (layers 1 through 3). It was developed to describe how data passes into and out of public data communications networks. X.25 networks are in use throughout the world.

Document: ISO 8208.

Several other ITU-T recommendations are relevant to packet switching: X.3, X.28, X.29, X.75.

(1996-08-10)