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Re: Honest Cogent opinions without rhetoric.

  • From: Peter Cohen
  • Date: Wed Mar 08 08:36:00 2006
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On 3/8/06, Todd Underwood <[email protected]> wrote:
>
>
> On Wed, Mar 08, 2006 at 01:56:00AM -0500, [email protected] wrote:
>
> > (from Marty)
> > >  From a global perspective[1], the top 12 (I stopped at Cogent since you
> > > are asking about them) service providers whose customers and peering
> > > partners reach the largest number of networks are listed below. You can
> > > make some fairly interesting assumptions on your own:
> > <snip>
> >
> > This gotta be the most meaningless metric ever. What does "reach"
> > mean?
>
> now, that's a bit harsh.  'incompletely specified in this email',
> perhaps, but 'meaningless'?  come on.  :-)
>
> the marketing description for those rankings is: "Identify service
> providers who are responsible for meeting Internet transit needs
> (directly or indirectly) of significant numbers of large customer
> networks within a given market, including both customer and peering
> relationships."
>
> in actual, technical detail, what that means is that we take global
> routing data (routeviews-style), determine the relationship of every
> edge (customer, provider, peer), and weight the 'downstream cone' (a
> caida term that is useful here) of each provider by the scaled prefix
> space and the degree to which that provider actually provided transit
> to that prefix space over the course of time.  it's critical to
> integrate across time and across lots of peers in this process.
> otherwise, the position of your peers and leaks come to dominate the
> equation.
>
> this metric (one of several that we've begun calculating daily) isn't
> perfect, but we've found that for large SPs it matches expectations of
> people familiar with traffic flows.
>
> > Note that many Cogent customers, while using Cogent for outbound, prefer
> > not to announce any routes to Cogent for political reasons (or prepend or
> > depref their routes). So, that metric won't be exactly helpful.
>
> this is, in fact, a useful point.  detecting and compensating for
> asymmetric routing is difficult in a metric such as this, although
> it's probably not impossible.
>
> t.
>
>
> --
> _____________________________________________________________________
> todd underwood                                 +1 603 643 9300 x101
> renesys corporation                            chief of operations & security
> [email protected]                               http://www.renesys.com/blog
>


Drew:
What i would do is construct an RFP with specific questions about
capacity, availability and locations (plus other things i can't
remember right now) so that I knew what i was getting  into with any
provider on if they were congested.   We see them all the time for
large deals, and i'm sure other providers do too.    A decision to
purchase from supplier A vs. B should not be done lightly, and without
some due diligence pertaining to where YOUR traffic may be coming from
or going to.  Perhaps a spread sheet of some sort that allows you to
consolidate all the responses.

Good Luck   Peter Cohen