Attempt to summarize Links on the Blink

Avi Freedman freedman at
Mon Nov 13 16:16:14 UTC 1995

> I would like to try to understand better where this discussion seems to 
> have come to rest.  Yesterday the suggestion was made that the major 
> providers add more bandwidth to their backbones.  There seemed to be no 
> assertion as to how this could be done.
> 1.  OC-3 is not yet routable on backbones.  Is that correct?

Well, I was told that the Cisco AIP card can talk point-to-point to another
AIP card at OC-3 speed using either HDLC or PPP.

> 2.  What is the routing impact of parrallel T-3s?  Or the creation of a 
> mesh of T-3s? I have the impression that this is not feasible because it 
> would expand the routing tables unacceptably or because of the questions 
> of how you would load balance among them??

If data can be routed on parallel T3s on a per-connection basis so that
there isn't a scrambling of ordering of packets per connection, then some
benefit is achived, though no single application or site can use more
than a T3 of bandwidth.

> 3.  There seems to be some consensus that we will see an increase in the 
> numbers of NAP or MAE like interchange points which could cut down on the 
> traffic that must traverse long haul backbones.  *BUT* doesn't each 
> additional interchange point used by all the top level providers mean 
> another new set of global routes crowding router memories?

It depends.  If routing decisions are made locally and the routes heard
at smaller or private exchange points by NSP x are not distributed to
NSP x's larger peering/route-decision routers, then possibly no.  That
would mean only hearing routes at private exchange points that were also
heard elsewhere (at a major peering point).

> 4.  How much help will regional NAPs like Tucson be?  Their goal is to 
> keep local traffic local and off long haul backbones.  What liklihood is 
> there that these will grow in numbers quickly enough to make a 
> difference?  If the majors start showing up at these points does their 
> arrival mean that the problem of crowding memory in their backbone 
> routers will be increased?

See above.


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