the Internet Backbone

Michael Dillon michael at
Fri Apr 5 21:59:45 UTC 1996

On Fri, 5 Apr 1996, Paul Ferguson wrote:

> Better yet, call it the 'default-free core', which is ironically what it
> is already called.  :-)

OK, how about this...

The core of the US Internet, also known as the default-free core, no longer 
follows a backbone topology. The core is composed of the major NSP's who 
operate national backbones providing national transit and who interconnect
at all or most of the public exchange points.

So, to determine whether a carrier is part of the core:

Are they an NSP?
Do they operate their own national backbone?
Can they provide national transit over their own network infrastructure?
Do they interconnect with other NSP's who satisfy the previous two 
conditions at most of the public exchange points?

Is this better? 

Michael Dillon                                    Voice: +1-604-546-8022
Memra Software Inc.                                 Fax: +1-604-546-3049                             E-mail: michael at

More information about the NANOG mailing list