May 1994 1. This document describes how Novell IPX operates over various WAN media. It is strongly motivated by a desire for IPX to treat ALL wide area links in the same manner. The IPX WAN protocol operation begins immediately after link establishment. While IPX is a connectionless datagram protocol, WANs are often connection-oriented.
Different WANs have different methods of link establishment.
The subsections of section 1 of this document describe what link establishment means to IPX for different media. When a router detects this, it will immediately reflect the lost connectivity in its routing information database instead of naturally aging it out. 1.2 Operation over X.25 Switched Virtual Circuits With X.25, link establishment means successfully opening an X.25 virtual circuit. Furthermore, each IPX packet is encapsulated directly in X.25 data frame sequences without additional framing. Either side of the virtual circuit may close it, thereby tearing down the IPX link.