Mythology and Folklore of Network Protocols

It's natural to assume that network protocol design is by now a well-known science, where the designers of today's standards take care to understand the tricks and pitfalls learned from previous protocols. This talk dispells this and other myths. It is intended to be provocative, making people question the things people assume are true; instructive, giving hints as to how to avoid some of the problems in future protocols; and inspirational, convincing students that there are ample opportunities to make contributions. This talk discusses wrong turns that have been made, such as what necessitated the invention of bridges, and what caused IP multicast to be unimplementable. It also talks about how a protocol, even one “proven correct”, can go horribly wrong, such as the unstable ARPANET protocol for distributing routing information. It talks about “obvious” tricks such as version numbers, that even today protocol designers insist on misusing. And it covers some of the areas in which research is most needed. Radia Perlman's work has had a profound impact on our field. She is the inventor of the spanning tree algorithm used by bridges/switches, and a lot of the technology behind modern routing protocols, including robust distribution of routing control messages, designated routers for scalability of multiaccess links, and robust parameter management. She has also analyzed IP multicast and identified the problems with the model that made all designs so complex and unscalable, and introduced the modification to the design (extended address multicast, also known as "simple multicast") that would fix these problems. Her thesis on robust routing in a network despite malicious packet switches is an important proof of concept for this important new denial of service attack. She has most recently been concentrating on network security issues, including analyzing and redesigning IKE, the key distribution protocol for IPsec, and scalable PKI models. Radia is a Distinguished Engineer at Sun Microsystems. She is the author of Interconnections: Bridges, Routers, Switches, and Internetworking Protocols, and co-author of Network Security: Private Communication in a Public World, two of the top 10 networking reference books according to Network Magazine. She is one of the 25 people whose work has most influenced the networking industry, according to Data Communications Magazine. She has an S.B. and S.M in Mathematics and a Ph.D. in Computer Science from MIT and about 50 issued patents. She was recently awarded an honorary doctorate from KTH, the Royal Institute of Technology in Sweden. Proceedings of the 27th Annual IEEE Conference on Local Computer Networks (LCN’02) 0742-1303/02 $17.00 © 2002 IEEE