Distinguished Lecture Series 2009-2010: Radia Perlman

Soul of a new network protocol
Radia Perlman (Sun Microsystems)

Abstract

Why is route calculation done at both layers 2 and 3 of
networking? Is one better? Do we need both? This talk explains the
historical accident by which bridging was conceived and the properties
that make it attractive, as well as dangerous, today. The talk
discusses new work being done in IETF known as TRILL (TRansparent
Interconnection of Lots of Links), which combines the advantages of
bridges (layer 2 forwarding devices) and routers (layer 3 forwarding
devices). Although the basic idea is fairly simple, certain properties
of bridges, such as their ability to create partitioned VLANs on a
layer 2 cloud, make the design challenging.