The reasons for co-location that have been mentioned so far include... - zero-mile circuits - a hardened location for equipment - to establish a local presence rather than building out one's own space. - skepticism about the value of the fast packet services; the skepticism has several flavors: - reduced bandwidth due to protocol overhead - less reliability than a shared FDDI - performance of ATM switches compared to FDDI switches 'Zero-mile circuit' isn't clear to me because, regardless of the technology used for the NAP, it's still necessary to purchase a circuit from your site to the NAP. The circuit is either included in the price of the fast packet service or purchased separately as a leased line to the co-location site. The next two points, 'hardened location' and 'establish a local presence,' make sense. If you do not have a presence in the city where the NAP is located, co-location serves that purpose. The various statements made concerning the value of the fast packet services are familiar arguments. I'd like to point out that CERFnet uses SMDS, the Northwest NAP (NIX) uses Frame Relay, and the San Francisco and Chicago ATM NAPs are carrying significant amounts of traffic. The Chicago NAP is experiencing peak traffic of nearly 80 Mbps. What is needed to move the debate forward are objective performance criteria and measurements, and I look forward to the work of the Benchmarking Methodology Working Group to provide that criteria. George Clapp voice: 201-829-4610 fax: 201-829-2504 page: 800-980-1298 email: clapp@bellcore.com