nanog mailing list archives

Re: Attempt to summarize Links on the Blink


From: Avi Freedman <freedman () netaxs com>
Date: Mon, 13 Nov 1995 11:16:14 -0500 (EST)

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.

Avi



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