Breaking down? It used to be that anyone connected directly
to an exchange point was tier one, and the tiers are pretty
obvious beyond that. Now that everyone's at the exchanges,
"tier one" is simply a marketing term.
I believe the latest common definition of tier 1 in that of an ISP with no
When we started we had a nontransit, 2 cisco 7206, IP only, star topology
(with arms to 5 international POPs), one customer network. Is this now
being defined as tier 1 since we were doing nontransit only?
I believe that "Tier-1" no longer means anything. It was a term
that had meaning when the government got out of the business of
running NSFNet, and created "Tier-1 Providers" that connected to
"Tier-2 Providers". At that time (if perhaps only for a fairly
brief time) there were actual defined tiers, and they ment something.
The mutation of "tier 1" to mean "transit free" is questionable at
best. After all, if you're transit free, you should just advertise
that fact if you think it's important.
That said, many marketing folks still want to use the term "Tier-1".
When a prospective customer asks me if my employer is "Tier-1" I
always respond with "What does Tier-1 mean to you", and then address
their specific concerns. You get some wildly different answers too.