(SPX) A transport layerprotocol built on top of IPX.SPX is used in Novell NetWare systems for communications in client/server {application programs}, e.g. {BTRIEVE} ({ISAM} manager).SPX is not used for connections to the file server itselfthis uses NCP.It has been extended as SPX-II.SPX/IPX perform equivalent functions to TCP/IP..[Better reference?](1999-05-27)