X.25 switching

You can use devices supporting X.25 switching as small-sized X.25 PSEs to protect the investment in X.25. Figure 123 describes the relationships among LAPB, X.25, and X.25 switching.

In addition to X.25, LAPB can carry IP when two devices are directly connected without an X.25 network in between. With an X.25 switching module, a device can work as a small-sized PSE to directly forward packets without using the upper layer service.