The Great Exchange
Tom Perrine
tep at SDSC.EDU
Wed May 27 23:25:39 UTC 1998
>>>>> The moving finger of Hal Murray, having written:
Hal> I think the right question is: How much local traffic will there
Hal> be and is that enough to make local shortcuts cost effective?
Hal> Part of that discussion may involve what "local" means.
Actually, I think a more important question will be "*where* do we mean
by local"?
In large metro areas, or any place with a large *number* of ISPs,
there will be advantages to local interconnects. Period. Even if
there is distance-insensitive pricing for their connection to a
MAE-thing, I would think that they would rather save that precious
bandwidth for traffic that really needs to go to the MAE-thing. It
could reduce their need to buy a bigger pipe to that major
interconnect, just to carry that local traffic "up-and-back".
I also can't see how a local interconnect could not be cheaper than a
long-haul up to a major interconnect. Considering that many of the
locals are co-ops, or non-profits, with cheaper(?) local circuit
costs, lower "membership" rates, etc.
Also, it is a "commons" thing: If there are no "local" interconnects,
then the MAE-things will always be on the verge of oversubscribed in
relation to the traffic carrying ability of the technology. Are the
major interconnects running at 20% or 80% (or 99%) of the capacity of
the underlying fabric? I don't know for sure, but I can hazard a good
guess :-) What will happen when the next 10 ISPs buy OC3+ circuits
into a major interconnect?
If the on-line poplulation is small, or if a majority (or oven if a
large minority) of the on-line population is served by a single ISP,
then a local interconnect makes less sense.
Also, don't forget to count univerities as ISPs; UCSD was the largest
single ISP (if you consider local customers) in San Diego until cable
modems got started. Now, even though cable modems are more common,
UCSD is still one of the major "targets" of those cable modem users.
I'm sure that this not an unusual situation.
I think that the key is the "diversity" factor of the traffic, in
addition to the basic population size.
--tep
More information about the NANOG
mailing list