X.25 Overview

It is conventional to represent an X.25 network as a cloud, as in Figure 2-1.

Figure 2-1 X.25 Overview

As Figure 2-2 shows, X.25 defines the way the interface between a system running X.25 (often referred to as a DTE) and a system providing a network connection (often referred to as a DCE) works. There is almost always a modem between the DTE and the DCE to handle the physical connection. However, this is transparent to X.25. X.25 does not define the means of transmission that should be used between the two DCEs.

Figure 2-2 X.25 Detail