Level 3's side of the story

Sat Oct 8 20:37:29 UTC 2005

On Oct 8, 2005, at 3:07 PM, Richard A Steenbergen wrote:

> Teleglobe depeers Cogent due to various ratio and market pressure  
> issues.
> Of note is that Cogent has recently entered the Canadian market where
> Teleglobe has a strong presence, and has started giving away free or
> nearly free transit to large inbound networks. Teleglobe is a Sprint
> customer, and Cogent reaches Sprint through Verio. Teleglobe is caught
> completely off-guard when Cogent refuses to accept the route via  
> Sprint
> transit, and blocks traffic between the networks. This continues for
> several days, until eventually routes are leaked/added from  
> Teleglobe to
> SAVVIS (AS3561), who Cogent peers with. This continues for a few  
> days more
> until Teleglobe finally agrees to repeer Cogent.

[SNIP]

You mention at least twice (here and in the FT depeering paragraph)  
that Cogent "accepts" the routes.

It is entirely possible, and in fact likely IMHO, that the prefixes  
were never offered by Verio to Cogent.  Cogent pays Verio for partial  
transit, why would Verio give Cogent more ASes than they paid for?   
If Verio doesn't announce the prefixes, how can Cogent filter them?

Of course, I do not have enable on Cogent or Verio border routers, so  
I cannot say for certain.  Would anyone who _knows_ care to enlighten  
us?

-- 
TTFN,
patrick