Sending vs requesting. Was: Re: Sprint / Cogent

Patrick W. Gilmore patrick at
Sat Nov 1 16:45:31 UTC 2008

On Nov 1, 2008, at 12:05 PM, Chris Adams wrote:
> Once upon a time, bas <kilobit at> said:
>> I've heard eyeball networks refer to traffic flows as sending too..
>> "You content hosters are sending us too much traffic, we want money  
>> to
>> upgrade ports and transport all that traffic"  Complete reverse logic
>> imho. It is always eyeball network customers that request data.
>> (except for a small portion of iphone/blackberry push email, but that
>> can't account for much.)
> Traffic sources tend to be concentrated in large data centers  
> (easier to
> service), while traffic sinks (DSL, cable, wireless) are widespread  
> and
> costly to upgrade.  The sink customers don't want to pay more (and
> there's at least some competition), so the sink providers look to see
> where else they get income to pay for their needed network upgrades.

Combined with hot-potato routing, the first part of that paragraph is  
a fancy way of saying "I have to carry the large packet a long way,  
you have to carry the small packet a long way".  It is not "fair".   
This is almost a good reason, but not quite.  (It can also be offset  
by moving the source next to the sink, through cold-potato routing /  
MEDs, anycast, CDNs, etc.)

The second part is a good business reason.  Profitable revenue is  
good, costs are bad.

There are good business reasons not to pay the sink as well.  But  
neither decision is obvious or the same for everyone.

Peering is complicated, people should stop trying to generalize it.

Peering is a business tool.   For years & years many people have  
claimed that to "peer" you must be equal.  Bullshit.  If I can make  
more or spend less by peering, I should do it.  If not, I should not.   
Full stop.  Notice the complete lack of regard for how big you are,  
how much capacity your backbone has, how many ASes are downstream of  
you, etc.?  When I go to buy routers or hire employees or any other  
business transaction, I don't say "that router vendor is making more  
money than I am, so I won't buy from him".  If people applied  
"peering" logic to anything else, they'd be laughed out of a job.

Don't know about you, but I am in business to make money, not measure  
my anatomy.  How big the next guy is doesn't enter into my equation -  
other than how it affects my bottom line.

To be clear, it is entirely possible that peering does not save you  
money.  Vijay is right, most people can't measure their COGS to save  
their life.  And if the network in question cannot, there's no way in  
hell the prospective peer can.  If you are a huge point source of  
traffic and want to peer, I may save money by saying no and paying a  
transit provider to deliver the packet to me where I want it  
(especially at today's prices).  Fiber, routers, colo, NOC employees,  
engineers, etc., are all not free ya know.

You can claim my customers asked for the data and therefore I have a  
requirement to peer, but you would be deluded.  What my customer and I  
have agreed has _nothing_ to do with you or your needs.  You don't  
tell me how to run my network, and I won't tell you how to run yours.   

On the flip side, saying "you are not on 3 continents so I will not  
peer" is stupid of not peering costs you millions a year.  Stupid  
decisions abound in the peering ecosystem.

There are tons of other _business_ reasons to peer, or not to peer.   
But "we're equal" or "your customer asked for it" are not reasons,  
stop using them.


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