Hi NANOG We are a group of researchers and our focus is on the economy of interconnection in the Internet. My question is mainly about the various costs of an AS establishing a connection with another AS, including the costs charged by the colocation providers. I am familiar with most of the connection options such as public peering on IXP, and private peering through xconnects. My understanding is that in addition to the cost of transit that the smaller AS pays to the larger AS, in the former you pay a monthly fee to establish a link to the switching fabric and then you can connect to as many ASes that are member in the IXP, and in the later you need to pay for as many xconnects that you need to connect to as many ASes that you plan to peer with. Obviously in both cases there is the cost of being in the colocation and renting a rack or whatever. What are the other costs involved? How should the AS reach the colocation center in the first place? I don't think every network can dig a hole an lay cables. Who should they pay to get from one PoP to another? Do ASes have to pay for xconnect to connect their PoP in a data center to the rest of their network? I think there is no single answer as different businesses may have different pricing models. I hope the discussion can help me understand the whole ecosystem a little bit better. Best Regards Reza Motamedi (R.M) Graduate Research Fellow Oregon Network Research Group Computer and Information Science University of Oregon