Why do some companies get depeered and some don't?

What I mean is, how come networks like Teleglobe, Limelight, etc. don't get depeered by others, but Cogent does? I'm sure Cogent isn't the only one with bad ratios.

Those with bad or uneven ratios then purchase transit and don't let
themselves get depeered...

I'm sure someone else must've seen it before.

Surely even assymetric peering agreements are mutually beneficial... ISPs are also content providers, either directly or through their customers... peering is going to have a flow-on effect in terms of reducing the cost of offering content to the people you peer with too, right?

Why all the focus on even or non-even-ness of up/down ratios in the first place?


Isn't it because the receiver is more likely to backhaul the traffic further, due to hot-potato routing - at least in the case of large networks with multiple points of interconnect?


That's the reason given. One can argue over whether it is the "real" reason.

Since we just had a long and thorough discussion of this in the last few days on this very list, perhaps the people who are wondering about this could read the archives and not bother the other 10K of us on something we answered _yesterday_?