Complete Protocol dictionary, glossary and reference
PUP: PARC Universal Protocol
PARC Universal Protocol (PUP), also known as PARC Universal Packet, developed at Xerox PARC, is an early internetworking protocol suite for network routing and packet delivery. In the 1980s Xerox used PUP as the base for the Xerox Network Services (XNS) protocol suite; some of the protocols in the XNS suite (e.g. the Internetwork Datagram Protocol) were lightly modified versions of the ones in the PUP suite, but others are quite different, reflecting the experience gained with PUP.