IXes and AS length

[Mike Hammett <nanog () ics-il net>]

So I just found out that the IX we're looking to hook up with (Equinix) doesn't allow downstream ASes. How does that 
functionally work? 

Stepping outside my ISP for a moment, I know a building owner with several buildings that provides Internet to his 
tenants. He's getting an AS so he can have upstream diversity. Unless carrier A or ISP B have direct private peering 
with whomever (Amazon, NetFlix, Google, FaceBook, etc., etc.), that building owner doesn't have a route to those 
services? They can't utilize carrier A or ISP B's public peering connection? How can that possibly bee with with every 
ISP being required to have their own physical presence on the exchange? That's just not practical. 

I understand not having parallel ASNs (advertising both ASN A and ASN B separately) from a sales perspective, but I 
don't understand ASN A advertising directly on the IX, but not allowing ASN A's downstream customers of ASNs B, C, D 
and E. 

Am I wrong or is this just an Equinix thing? 




----- 
Mike Hammett 
Intelligent Computing Solutions 
http://www.ics-il.com