(sPX) A transport layerprotocol built on top of IPX. sPX is used in Novell NetWaresystems for communications in client/server {application programs}, e.g. {BTRIEVE} ({IsAM} manager). sPX is not used for connections to the file server itself this usesNCP. It has been extended assPX-II. sPX/IPX perform equivalent functions to TCP/IP. . [Better reference?] (1999-05-27)