packet exchange protocol (XNS) (PEP)
The functionality of the Packet Exchange Protocol(PEP) developed for Xerox Network System( XNS) is the same as that of the connectionless UDP protocol.
Packet Exchange Protocol (PEP) is a layer 4 XNS protocol that has a 32-bitID data field to uniquely identify the data packet in the dialog structure. The ID number is specified by the client and used by the server for its response to the client.