Speaker: Amund Kvalbein, Simula Research Laboratory
Title: On the Scalability of BGP: the roles of topology growth, 
          policy and update rate-limiting 

Abstract:

The scalability of BGP routing is a major concern for the Internet
community. Scalability is an issue in two different aspects:
increasing routing table size, and increasing rate of BGP updates. In
this paper, we focus on the latter.  Our objective is to understand
the role of three fundamental factors that are related to either BGP
or to the growth and evolution of the Internet. These factors are,
first, the way in which the Autonomous System (AS) topology
grows. Second, the use of policy-based routing and of
(settlement-free) peering relations between ASes. And third, the BGP
update rate-limiting timer (MRAI), considering both major variations
with which it has been deployed.  We consider these three factors in
several ``what-if'' growth scenarios that are either plausible
directions in the evolution of the Internet or educational corner
cases. Our findings explain the dramatically different impact of
multihoming and peering on BGP scalability, identify which topological
growth scenarios will lead to very fast increase in BGP churn, and
emphasize the importance of not rate-limiting explicit withdrawals
(despite what RFC-4271 recently required).