The Extent of AS Path Inflation Caused by Routing Policies
by Lixin Gao, Feng Wang
url show details
Details
| abstract: | Border Gateway Protocol (BGP) is an interdomain routing protocol that allows Autonomous Systems (ASes) to apply local policies for selecting routes and propagating routing information. These routing policies are typically constrained by the contractual commercial agreements between administrative domains. For example, an AS sets its routing policy so that it does not provide transit services between two of its providers. As a result, a route in the Internet may take a longer AS path than the shortest AS path. In this paper, we systematically analyze AS paths and quantify the extent that routing policies inflate AS paths in the Internet. Our results show that AS path inflation in the Internet are more prevalent than expected. We first present the extent of AS path inflation observed from the Route View routing tables. We find that from an ISP, at least 67% of AS paths are inflated by at least one AS hop and AS paths can be inflated by as long as 5 AS hops. We then employ two typical routing policies to show the extent of AS path inflation for all AS pairs. We find that at least one AS hop and AS paths can be inflated by as long as 9 AS hops given a typical routing policy model. Quantifying AS path inflation in the Internet has important implications on the extent of routing policies and traffic engineering performed on the Internet, and BGP convergence speed. | | type: | misc |
|
|
You need to log in to add tags and post comments.
