Paul Francis
Computer Science Department
Cornell University
"Scaling Internet Routing with Legacy Routers"
Abstract:
The large and constantly growing Internet routing table size is a longstanding problem that limits multihoming, slows convergence time, and requires periodic equipment upgrades. This problem may get significantly worse in the next few years as IPv4 address space exhaustion leads to an increasingly fragmented address space. While there have been many solutions proposed over the years, a number of them by the speaker, all of them are too disruptive. In this talk, we present a way to shrink routing tables, easily by an order of magnitude or more, without any software changes to routers, and without requiring any cooperation between ISPs. The idea behind our approach, called Virtual Aggregation, is to partition the address space into large Virtual Prefixes, each of which is delegated to a tunneled virtual network composed of a fraction of ISP routers. This talk describes how Virtual Aggregation can be configured and deployed, and gives performance results based on measurements made at a Tier-I ISP.
Bio:
Paul has been a researcher in computer networking for going on 20 years now, in such organizations as MITRE, Bellcore, NTT Software Labs, and ACIRI. Within computer networking, Paul's work has centered on routing and addressing, with a particular liking for problems having to do with large and self-configuring networks. Work in this vein extends from Landmark Routing, done in the late 80's, through Yoid end-system (overlay) multicast (late 90's), to recent work on unstructured P2P networks and more scalable end-system multicast. Notoriously, Paul is the inventor of NAT (demonstrating originality, if not business acumen, judging from his bank account). Other innovations of Paul's include shared-tree multicast, IDMaps host proximity service, shortcut routing (through large non-broadcast subnetworks), and the multiple-addresses approach to site multi-homing, which is the basis for scalable routing in IPv6. Paul joined Cornell University in 2002, where he has worked on IP anycast services, new network management architectures, BGP scalability, overlay multicast, random node selection in P2P networks, new transport protocols, E2E approaches to DoS and worm prevention, and new naming and addressing architectures for the Internet.
Thursday, September 18,2008
3:00 - 4:15
Wu & Chen
101 Levine Hall