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Re: Honest Cogent opinions without rhetoric.
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, 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