On Sun, 10 June 2001, Sean M. Doran wrote:

Rachel Warren <rachel@telco-bitch.com> quotes Bill Manning and replies: | > There was never any governmental sanction of the term or | > concept of tier anything associate with the NSFnet or its | > transition. | | And this is definately a good thing.

It's also not true. NSF 93-52 did indeed specify precisely what type of backbone the funded regionals could connect to, and it required those distinguished backbones to interconnect in specific locations (the "priority" NAPs).

The name "tier" wasn't used wrt eligible and ineligible backbones, but there was an explicit ranking of preference by the NSF that was based on specific interconnectivity, and that mapped very cleanly onto the then tier-1 backbones, with the exception of UUNET, which didn't play (and MFS's NAP wasn't even a "priority" one).

The NSF only specified connectivity to the NAP, not interconnectivity between providers. Due to problems with various NAPs, who connected to what was always in flux. For example, the Chicago NAP was designated a "priority NAP." But networks service providers (NSPs) were very slow to connect to chicago. I believe ANS went through various periods of not connecting, connecting, and disconnecting at the Chicago NAP. MCI's connection to the chicago NAP didn't work for months at a time. Well, the MCI vBNS connection worked, but the InternetMCI connection didn't. There were some networks which didn't connect to either of the ATM NAPs (Chicago and San Francisco) because their engineers didn't like ATM. They only used the Gigaswitch based NAPs. UUNET and Genuity are examples of networks which declined to connect to the ATM networks for a long, long time. If I recall my history, PSI and AGIS were the first two networks to connect to all the priority and non-priority NAPs of the day (Chicago, New York, San Francisco, MAE-East and the de facto CIX router). A Sprint engineer was one of the most vocal opponents to the ATM naps.