4 - SPP - Sequenced Packet Protocol
SPP was developed by Xerox as part of the XNS pro tocol suite; it has been adopted by various other manufacuters. The most popular variant is Novell's SPX.
4 - SPX - Sequenced Packet Protocol
SPP is a connection-oriented transport protocol; connectionless services are provided by PEP.
4 - PEP - Packet Exchange Protocol
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