"Circuit-based vs. connectionless" and other design choices for networks

Simon Leinen

For many years, networkers have struggled with the connectionless nature of the dominant IP backbone technologies. There have been numerous attempts to (re-) introduce circuits into our networks using technologies such as X.25, ATM, MPLS, and now GMPLS and other "lightpath" protocols. So far, best-effort unicast IP has resisted these efforts and remains the dominant service. This talk will look at the issue of circuit-based versus connectionless networks, putting it in context of other design choices. In addition, I will suggest a different direction for network evolution as an alternative to adding circuits, namely taking path selection ("routing") out of the network.