<<As I understand it, NETIPC and TCP/IP are two different implementations of sockets and one can not substitute for the other. Is this incorrect?>> Totally (sorry ;-). TCP/IP is a network transport (actually, it's two different pieces, but that's another story). Other (mostly) comparable transports are things like SPX/IPX, X.25, and NetBEUI. Sockets is a network-programming interface. IOW, it's a way for applications to talk to the networking system without having to go into excruciating detail about how the networking actually happens. HP's NetIPC sockets can be used for communication over links using either X.25 or TCP/IP. Berkeley sockets are generally TCP/IP-only. Windows NT sockets use TCP/IP, SPX/IPX, NetBEUI, or AppleTalk. A given system can implement sockets over a number of transports; the idea of the socket interface is to make the network look, as much as possible, the same from "above" independent of what's actually running underneath. Steve Dirickson WestWin Consulting (360) 598-6111 [log in to unmask]