Subject: RE: Newbie Question about addressing impacts

From: "Christian Huitema" <[email-masked]>
Date: Sat, 14 Aug 2004 23:23:54 -0700

> If we grow the Internet routing table to say 1e6 routes, then the VPN
> demands will be something like 1e7 or 1e8.  This will be yet another
> tax on the carriers and will get passed on to us, the consumers.

I am sorry, but I don't get the VPN point. The number of VPN is
proportional to the number of sites willing to establish VPN
connections, and not linked to the availability of global addresses for
these sites.

Eric is making a basic point of economics. Large companies will want to
get a global address, effectively shifting network management cost from
their IT department to the ISP community. A number of folks in this
group believe this is a bad idea, and are essentially trying to write in
the standards that such cost shifting should be illegal. I personally
don't think it should be illegal, although I am ready to admit that it
should be expensive, as in "no free lunch".

Your mention that routers commonly support 1E6 routing entries seems to
indicate that some amount of "cost shifting" is indeed feasible.

By the way, routing in a flat space of 10 billion entries is also
feasible, using distributed hash tables. However, with the current
algorithms, the average path length will be markedly larger than the
shortest path.

-- Christian Huitema

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From: Tony Li <[email-masked]>
Date: Sun, 15 Aug 2004 01:19:18 -0700

> connections, and not linked to the availability of global addresses for

If PI addresses are made widely available, then the routing table will
grow.  As the routing table grows, each carrier must grow its tables
to support default-free routing.  To be able to provide VPN services, 
the
carrier must be able to support all of the routes that his customers
wish to support.  Since several of these customers could reasonably
be Tier 1 backbones, they will be carrying the full table.  Thus, there
is an amplification factor (currently about 10x) of the size of the
table vs. what routers have to hold.  If that grows (as seems likely
as the size of the DFZ grows), then the amplification times the
natural growth of the table will continue to push technology.

> should be expensive, as in "no free lunch".

Well, I don't think that "illegal" is possible, given that we are not
a legislative entity.  I don't think that anyone would object to a
market for routing table entries, but it has yet to appear.

> indicate that some amount of "cost shifting" is indeed feasible.

No, I don't think that's sufficient.  We have yet to see any type of
cost shifting occur.  For that to happen, we would have to have a market
and the fact that it does NOT exist means that we don't have a mechanism
to work with.  Yes, this is an economic, not technical issue.  However,
we as technologists have the responsibility to raise the awareness of
this and to promote prefix conservation.

Tony