In article , "Bill Silvey"
wrote:

Hey all...

Has there been a move towards using consumer goods, particularly
electronics, on military a/c? I was watching something about the AWACS
recently and I thought to myself "I wonder how those systems are all
networked." - which set the ball rolling and I began to wonder if indeed
there were coax or RJ45 connectors someplace underneath all of that leading
into 10/100 or 10BaseT network cards.

Yes and No.
For systems intended for transport platforms where the environment is
fairly benign, ruggedized commercial or even pure commercial
may work. These systems do not usually meet long-term reliability
and life requirements though, and are usually larger and heavier than
purpose-built military systems.
For pointy nosed aircraft, it's rare to see COTS. The environment is too
severe, and space and power constraints too much.
Lots of co-ax, but usually better performing connectors than commercial
RJ45s.
From a functionality standpoint, networks need to be much more secure
that commercial hardware and software can provide. Often the airborne
networks and NICs are high-rel, secure derivatives of commercial
hardware and software. If you can get a copy of the Fibrechannel
Avionics Environment spec, you can see that it is a subset of the commercial
Fibrechannel set of specs, which defines those functions necessary for
avionics and military use that are not necessarily present in the
commercial version. We had to work with the commercial guys for years
to make sure certain things were in the commercial specs so we could
use them in the avionics spec, even though the commercial guys didn't think
they needed them. I mention FC because it is the most widely used high-
bandwidth network going into military fighters.
Real time performance and deterministic behavior are also crucial in
avionics applications. Much of what passes for "real time" in commercial
networks is woefully inadequate for military or even commercial avionics
use.
This is a huge subject with many details.

--
Harry Andreas
Engineering raconteur