[tt] IPv4 address length technical design

Thu Oct 4 08:49:16 UTC 2012

On Thu, Oct 04, 2012 at 05:10:00PM +0900, Masataka Ohta wrote:

> > Above describes your setting for the next protocol. There is not
> > a lot of leeway in design space, I'm afraid.
> 
> Just keep using IPv4.
> 
> 						Masataka Ohta
> PS
> 
> See ftp://chacha.hpcl.titech.ac.jp/IEEE-ST.ppt presented
> at a summer topical of IEEE photonic society.

Thanks for the Powerpoint, I've already seen it or an
earlier version of it.

My (minor) beef with it is that while you offload most of
heavy lifting to photonics you still use electronics and
lookup. It is however reasonably easy to do everything
at effectively L2 with a photonic crossbar if you encode
geography in the headers (you have a direct proximity
metric on your link slots).

(You can actually prototype this with Ethernet MACs,
as 2^48 in square meters happens to be half the surface 
area of the Earth http://www.wolframalpha.com/input/?i=2^48+m^2
So MAC collisions are not very probable, if distributed
optimally ;)

If you do it in optics the protocol is completely different
from IPv4/IPv6, so you would encapsulate and use it as
a transport layer for legacy (ha!) protocols.

P.S. Sorry for shit-stirring (and it ain't even Friday yet).
     I'll be good now.