10.1 How DLPI Works

DLPI defines the format that STREAMS messages must take when interfacing to the datalink layer. The diagram below summarizes the way it works:

Figure 10-1 DLPI Summary

Like NLI, DLPI uses the putmsg and getmsg system calls and certain ioctl commands. See Chapter 11, DLPI Reference for more information.

The DLPI message primitives provided support LLC and LLC1 as well as LLC2. However, as LLC and LLC1 are not used by Solstice X.25, this is not documented here. Refer to A STREAMS-based Data Link Provider Interface--Version 2 for information on working with LLC and LLC1.