Thanks Howard. I had just been wondering about this very topic myself. You
plugged one of your books, but I learned a lot about this same topic from
another one of your books, which I will plug! :-)
WAN Survival Guide
That book is really helpful for people like myself who mainly work on the
other side of the equation, as a customer of the ISPs at various tiers.
Well, I do help (part-time) run a small ISP, but I think it would be Tier 5
at best. :-)
Priscilla
Howard C. Berkowitz wrote:
>
> At 5:33 AM +0000 6/27/03, Mwalie W wrote:
> >Hi All,
> >
> >This should be a simple one.
> >
> >I have heard that we have Tier 1, Tier 2, Tier 3 ISPs.I do
> assume we only
> >have Tier 1 and Tier 2 in the US, Europe and Asia (Japan,
> China).
> >
> >In a third world country, can we have Tier 1 and Tier 2? Or we
> just have
> >Tier 3 ISPs which connect to Tier 1 and Tier 2 in the USA, etc?
> >
> >Okay, I ask this question because I was reading an article in
> Kenya about a
> >local ISP there called UUNET-Kenya (www.uunet.co.ke) and they
> are saying
> >that they are a Tier 1 ISP. I did not think that that Kenyan
> ISP is Tier 1,
> >but I do know that its parent company (Worldcom?) is Tier 1.
> >
> >Was it just marketing to the locals there??
> >
> >Thanks for your answers
>
> The tier concept is mostly marketing these days, although there
> is
> some technical basis.
>
> An essential part of the difference is the relationship of the
> provider to other ISPs. Unfortunately, the terminology is
> awkward
> here, because there are two meanings of the word "peer". The
> familiar
> one is a BGP session, regardless of economics. The other
> definition
> is an economic one. A "peer relationship" means that the two
> ISPs do
> not charge one another for transit and send at least full
> customer
> routes to each other, on the basis they are both of about the
> same
> aize and it's to their mutual advantage to let their customers
> have
> access to each other, without worrying about the billing.
>
> The other relationship is a customer-provider one, where the
> "less
> valuable" provider buys transit from the "more valuable" one.
> In
> other words, if ISPs are peers, no money changes hands.
>
> A tier 1 provider never buys transit. It gets all its routes
> from
> bilateral peering arrangements. It will have a 24/7 network
> operations center, and a national or intercontinental
> transmission
> network, either leased or physically operated, of at least DS-3
> (more
> likely OC-3 to OC-48 these days). Its non-provider customers,
> if it
> has them, will usually be large enterprises only -- it's really
> a
> wholesaler.
>
> A tier 2 provider is regional and gets all its regional routes
> through peering arrangements. It does buy transit to go
> outside its
> region, although it's likely to have significant bulk
> discounts. It
> has 24/7 NOC and a broadband transmission network within its
> region.
>
> A tier 3 provider buys transit from multiple upstreams and runs
> a
> default-free routing table. It may or may not operate a
> significant
> transmission network. Usually, if it doesn't have a full 24/7
> NOC,
> technical support remains available to other providers (not
> necessarily customers) through pagers and the like.
>
> A tier 4 provider buys transit from one or more upstreams, with
> connectivity to multiple POPs of the same provider if it only
> uses
> one upstream. It does run BGP with a substantial part of the
> global
> table.
>
> A tier 5 provider is a reseller, perhaps an Internet cafe. It
> owns or
> leases ("virtual POP") end user access and buys transit.
>
> There are lots of refinements and variations. As a shameless
> plug,
> I'll mention my own book, _Building Service Provider Networks_.
> Geoff Huston's _ISP Survival Guide_ complements it, going
> further
> into the business model, as do the many papers on peering
> economics
> by Bill Norton of Equinix.
>
> Do I at least get a cup of Kenyan coffee for all this? I'm
> trying to
> remember some of the more solid dishes. For the people in the
> US, if
> you think "what's the best CCIE number" is bad, try a
> discussion
> among various African cultures as to who makes the best Joloff
> rice!
>
>
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=71550&t=71508
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
