Dear all, I am a PhD student at EPFL, Switzerland. My recent research interest is in large scale differences between the commercial and academic parts of the Internet. Of course, in order to perform this kind of studies I need a way to distinguish between these two worlds. I've learnt that Abilene does not provide commercial connectivity. This means that BGP prefixes and AS paths announced by Abilene BGP routers should lead only to research and academic destinations. I have extracted (from the BGP tables at http://abilene.internet2.edu/observatory) a list of all such destinations and obtained 1333 ASes (for data form July 2006). The number looks reasonable, but I would like to be sure that I am not making a mistake. Therefore I would be grateful if you could answer the following questions: 1) Is this approach to obtain a list of research and academic ISPs correct? 2) Do you maybe know of such lists compiled before? 3) If I keep not only the destination ASes, but also all ASes on the AS paths towards these destination I obtain a list of about 1400 ASes. How should I understand this? Does it mean that some research and academic destinations are reachable from Abilene only by traversing the commercial Internet? 4) Of course, research and academic ASes are often well connected to the commercial Internet. My guess is that in most cases their peering relationship is "customer-provider", where commercial ASes are providers. Is it possible that an academic AS is a provider for some commercial ASes? If so, does it happen often? Thank you in advance for your comments. Maciej Kurant ============================================= EPFL IC ISC LCA3 Maciej Kurant PhD Student CH-1015 Lausanne, Switzerland web site: <http://lcawww.epfl.ch/kurant> http://lcawww.epfl.ch/kurant =============================================