On Tue, 02 May 2006 22:38:22 PDT, Robert Sherrard said:
What make a provider a tier 2, versus a tier 1 provider...
Usually it's defined as "Tier 1's don't buy transit, Tier 2's do". Of course, it gets a lot more complicated, because you can easily have a "Tier2" that's peering for 95% of its prefixes, and buying transit for 5% of not-often-used prefixes simply because it's expensive to get a peer for that 5%. But said Tier2 may be bigger than some "tier 1s", and be better on any *rational* comparison criteria (price, support, throughput, latency, jitter, downtime/SLA, path diversity, etc....) If a company is "almost a Tier1", but buys transit for several hundred prefixes coming from Korea and Nigeria (say, 0.2% out of the 180K or whatever the routing table is this week), why do you *care*, unless you have (or *seriously* plan to have) lots of packets coming and going to those 2 countries? In general, the people who *really* care about Tier 1/2 already know if they are a 1 or a 2 themselves. Almost everybody else falls into 2 categories: 1) People who are using 1/2 as a shortcut for doing a *proper* analysis of the options. 2) People who feel a marketing need to say "we peer with X Tier-1s". (OK, where's my asbestos long-johns? ;)
Is it possible to determine who a tier 2 (i.e. Cogent) leases fiber from?
Try asking? :) (And the answer will probably depend on which exact leg of their network you're asking about - it's almost certainly a patchwork....) It probably doesn't matter unless you're trying to buy connectivity over diverse paths - in which case you're going to have to ask *both* providers what the exact fiber routing is. It's possible the tier2 and the tier1 are both leasing previously-dark fiber in the same conduit - but leasing it from 2 different companies. And of course, it's quite possible that *this* week, that tier 2 is routing your packets over fiber they own, and next week, some traffic engineering puts your packets on fiber leased from A - and last week, it was on fiber leased from B. (Disclaimer: we're neither a Tier 1 or 2. And most of the routes we receive via a regional provider that treats us *very* nicely - mostly because we have them by the short-and-curlies. They piss us off too much, we turn off the phones in their NOC. ;)