Re: Tierwise ISPs

On Sat, Nov 28, 2009 at 10:41, Iwan Hoogendoorn <iwan_at_ipexpert.com> wrote:
> Hi Bhuvanesh ,
>
>
> A Tier 1 network is an IP network that participates in the Internet
> solely via Settlement Free Interconnection, also known as settlement
> free peering.

Ugh... I would be careful with this statement. This is highly
"politically wrong".

> Tier 3 - A network that solely purchases transit from other networks
> to reach the Internet.

What, it's not allowed to have any peers? How is that even possible? :-)

* * *

There have been *endless* discussions on this subject on both NANOG
and Cisco-NSP mailing lists. The common conclusion is that these term
"make no sense", i.e. there is so much disagreement about them, that
it needs to be left to analysis of the reader to determine which (I)SP
is in which group.

One of the more common examples used is Cogent - are they Tier-1 or
Tier-2? They don't have settlement-free peering, but only because some
of the "traditional" T-1 carriers downright refuse to peer with them,
accusing them of price dumping... There are other examples, as well.

As far as I'm aware, there no books that deal with this subject and
your best choice are mailing list archives and probably some academic
papers.

--
Marko Milivojevic - CCIE #18427
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