[nycbug-talk] Cogent and Sprint - a signal of things getting Oldschool?

Isaac Levy ike at lesmuug.org
Sat Nov 1 18:14:02 EDT 2008

Charles and Alex,

On Oct 31, 2008, at 8:13 PM, Alex Pilosov wrote:

> On Fri, 31 Oct 2008, Charles Sprickman wrote:
>> Nice.
>> I've not followed the ups and downs of ISP dramas in a long time,  
>> but my
>> gut feeling, even before reading the Renesys blog, was "oh, sprint  
>> still
>> sells internets?".  Personally, I think this hurts Sprint the  
>> most.  My
>> gut feeling is that they are something of a has-been in this market.
> It's complicated. Despite being a "has-been", sprint maintains the "we
> will not peer with you" reputation, and is the "hardest to establish
> settlement-free peering" carrier. As a result, many people end up  
> using
> only Sprint for transit (or, "the only transit we will admit to  
> having"),
> so they *can* get other peering (it's a bit complicated - basically,  
> if
> your transit is an existing peer, you won't get peering), in effect,
> helping Sprint maintain this status.
>> One thing that really has me wondering, and again, this is probably  
>> an
>> Alex question, is an odd situation I ran into a few years back...   
>> I was
>> toying around with two providers - L3 and HE.  I primarily wanted  
>> HE as
>> backup, since L3 was not really soaking us and they generally have  
>> their
>> shit together outside of the management/sales/install realms.  No  
>> matter
>> how much I prepended our HE announcement, I just could not squash the
>> inbound traffic.  Apparently HE buys transit from Cogent and there  
>> are a
>> TON of people that shove all outbound traffic down a Cogent link if  
>> they
>> have one.  This is not that much of a surprise (the volume of  
>> traffic was
> *snicker* Yes, cogent is the "transit we use for outbound but we won't
> admit to it".
> The answer, of course, is not prepending it, but setting community  
> flags
> telling HE to not announce this route to cogent, or to depreference  
> your
> route while announcing to cogent, or some such. I don't know the  
> community
> list for HE.
>> though), but the thing that puzzled me when I ran a bunch of stuff
>> through flow-tools was that I was seeing traffic from 1239 (Sprint)
>> coming in through HE via Cogent.  I'm still puzzled as to what that  
>> was
>> about - from my view, it looked like Sprint jamming traffic down  
>> Cogent
>> rather than L3 (I'm certain Sprint and L3 peer).
> It's complicated without looking at more details. You can't say  
> where it
> *really* came from. What *could* be easily happening is that someone  
> (X)
> only uses Sprint for inbound - so you see them behind Sprint. However,
> X uses everyone else for outbound (including Cogent), who will  
> obviously
> send it toward HE (paying customer).

This thread is mind-blowingly interesting to me.

This thread, and Miles' earlier email about 'hot potato' routing,  
makes me ask perhaps a stupid question:

Why is routing not synchronous?  Why is sending more expensive than  
receiving packets- from a transit perspective?


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