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Re: Request for Comments on a topological address block for N. Calif.
From: Sean Doran <smd () cesium clock org>
Date: Sun, 24 Sep 1995 13:30:43 -0700

| Right now, larger ISPs aren't getting large
| blocks, and they are allocating things in non-contiguous non-growable
| blocks, neither of which is good.  Nothing is being done to organize
| topological assignments at all, which is seriously not good.

If some registry were to give me a /8, I would carve that up
right now into ten chunks (one per SprintLink POP as of a
couple weeks from now) and subdivide those to take into
account possible growth into new cities before the current
allocations to end users were exhausted, and allow for
unexpectedly heavy or unexpectedly light allocations to
customers from those prefixes.

However, those ten chunks would be the only individual
prefixes announced out of AS1239 to the rest of the world,
in the entire /8.

Some parts of the world would even see the /8 and not the
ten individual per-POP prefixes.

This is what is done now with smaller chunks of address
space:


Block Name      IP Addresses
-------------------------------------------------------------------------------
East            198.67.0/17 198.69/16 199.0/16 204.117/16 204.180/16 204.183/16
                204.215/16 205.160/15 205.244/15 206.105/16
West            198.68/16 199.2/16 204.94/16 204.119/16 204.182/16 204.212/16
                205.162/15 206.107.128/17
South           199.1/16 204.96/16 204.181/16 204.214/16 204.251/16
                205.240/15 206.61.0/17 206.104/16
North           198.70/16 199.3/16 204.95/16 204.120/16 204.248/16
                205.242/15 206.106/17
NorthEast       204.97/16 204.213/16 204.249/16 205.246/15 206.106.128/17
SouthWest       204.118/16 204.250/16 206.61.128/17 206.107.0/17
ICM-Atlantic    198.67.128/17
NYSERNet        204.168/16 205.232/16

and with a best-fit algorithm for allocation to customers
(all done in nifty software written by Vadim Antonov), we
do pretty well in terms of site-aggregation and keeping
lots of subnets of these out of our backbones.

Unfortunately, the allocations we've been getting haven't
been very big, and so we end up having to introduce things
as long as 17 bits to the world, where we might have only
had to announce /16s and /15s with a larger delegation
from a registry.

Block Name    Total Free Used                   Free Blocks
               Cs    Cs         1   2   4   8  16  32  64 128 256 512 1024
--------------------------------------------------------------------------
East           2863  233  91%   1           1       1   1   1
West           2176   51  97%   1   1           1   1
South          2176   47  97%   1   1   1   1       1
North          1920  218  88%       1       1   1       1   1
NorthEast      1408  211  85%   1   1           1       1   1
SouthWest       768  173  77%   1       1   1       1       1
NYSERNet        512  129  74%   1                           1
ICM-Atlantic    128  122   4%       1       1   1   1   1
--------------------------------------------------------------------------
        TOTAL 11951 1184  90%   6   5   2   5   4   5   4   5


So, beacause we are clever and do a mix of provider-based
and geography-based allocation (but it is a mix of both,
with an emphasis on the provider part), we end up with
blocks that are starving, but a single huge allocation that
isn't full enough to have a new large allocation done by the
registry.

        Sean.



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