Xerox Network System
Xerox Network System
(networking)Implementations exist for 4.3BSD derived systems and theXerox Star computers. Novell based much of the lower layersof their protocol suite IPX/SPX on XNS.
The main components are: Internet datagram protocol (IDP),Routing information protocol (RIP), Packet Exchange protocol(PEP), and Sequences packet protocol (SPP).
XNS has strong parellels to TCP/IP in that the network layer, IDP, is roughly equivalent to IP. RIP has the samefunctions (and obviously name) as the routing informationprotocol, RIP. SPP, a connectionless transport layerprotocol, is similar to UDP. PEP is also in the transportlayer but is connection-oriented and similar to TCP.
XNS specifically is no longer in use due to the allpervasiveness of IP.
XNS denotes not only the protocol stack, but also anarchitecture of standard programming interfaces, conventions,and service functions for authentication, directory, filing,e-mail, and remote procedure call. XNS is also the nameof Xerox's implementation.
Many PC networking companies, such as 3Com, Banyan,Novell, and Ungermann-Bass Networks used or use avariation of XNS as their primary transport protocol. XNS wasdesigined to be used across a variety of communication media,processors, and office applications. UB, (now a part ofTandem Computers) adopted XNS in developing its Net/OneXNS routing protocol.