Sequenced packet exchange : SPX

Sequenced Packet Exchange (SPX) is an old Novell protocol used to manage the Novell Internetwork Packet Exchange (IPX) that allowed Novell Servers and clients to communicate over LAN (Local Area Networks) and WAN (Wide Area Networks).

The advantages of one machine easily finding another machine on the LAN was a disavantage on a WAN since it needed so much overhead. TCP/IP is now a more common protocol stack for both WAN and LAN.