photonic buffer bloat

Eugen Leitl eugen at
Sat Jan 28 11:58:05 UTC 2012

In future photonic networks (which will do relativistic cut-through 
directly in a photonic crossbar without converting photons to electrons 
and back) the fiber is not just a transport channel but also a photonic 
buffer (e.g. at 10 GBit/s Ethernet a short reach fiber already buffers 
a standard 1500 MTU). 

Of course photonic gates are expensive, individual delays do add up
so even with slow light buffers or optical delay loops taken into consideration 
current TCP/IP header layout has not been optimized for leading edge 
containing most significant switching/routing information, or even 
local-knowledge routing (with no global routes). It's too bad IPv6 
was not radical enough, so today's legacy protocols have to be tunneled 
through the networks of the future. 

I presume this future is some 20-30 years away still.

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