#error control protocol

Xerox Network Systems (XNS) and the OSI Model – Network Operating Systems

We need to take a brief look at the Xerox Network Systems XNS model developed at Palo Alto Research Center (Parc), because several of the major LAN vendors (notably Novell and Banyan) have based portions of their NOS on the XNS model. See the Xerox Network Systems (XNS) and the OSI Model diagram below.

Figure 6-6. Xerox Network Systems (XNS) and the OSI Model

Xerox used a very early version of…