22.9 Summary

Wide Area links have an increasingly important role to play in joining our LANs together. Gone are the days of single vendor solutions where proprietary protocols could be used. Today, multi-protocol multi-vendor networks are the norm and inter-operability is the watch word for router manufacturers. PPP provides us with this standardized functionality, and allows multiple protocols to operate over a single link. Indeed, the rich functionality offered is probobaly more than most people would ever need however, by having all this available within a single protocol is certainly glamorous.

Serial dial-up links also take advantage of protocols such as SLIP and PPP. Certainly of the two, SLIP is now least popular since it does not provide features such as Compression, Authentication, or multiple protocol support. However, being simple means that it is easy to implement and has little or no overhead on slow speed links. PPP on the other hand, although being more complex, provides us with a whole suite of protocols that enhance its functionality with Network Control, Compression, and Authentication Protocols.