Trick of Treat: A Halloween Peering Suprise
Yesterday, tens of thousands of Sprint and Cogent customers got an early
Halloween surprise. At 4pm EDT, Sprint and Cogent terminated
their direct peering relationship.
The below graph shows traffic from the perspective of 25 tier2 ISPs
around the world. All of these ISPs were direct customers of either
Sprint or Cogent. And all lost transit connectivity from Cogent to
Sprint (or vice versa).
For about all but a couple of these ISPs, traffic quickly moved to
alternative paths. Other ISPs like Verizon, Qwest, BT, Level3 (who had
their own peering dispute with Cogent last year) provided transit
paths between the now partitioned two ISPs. Though, at least one ISP
anonymously participating in the Internet Observatory lost
connectivity to Sprint customers (and continues to drop traffic as of
this blog posting). It pays to be multi-homed.
Why did Cogent and Sprint pull the plug on their peering relationship?
I have no direct information, but money, traffic ratios, and maybe
even egos are always a good guess.
In the unregulated ISP interconnect industry, peering is a lot like
trick or treating. Sometimes the competitive industry drives down
prices and gives customers a treat. But today some Sprint and Cogent
customers definitely got tricked.