Well, I know that NSA has its own undersea network, but I can only take a fairly crude guess as to what it might look like.
SInce it was several years ago, I guess I won't be getting into too much trouble mentioning some NSA work I participated in. It was not classified (though they probably wanted it to be, but we were one of the ultimate fiber optic consulting groups that just happened to be civilian, and NSA had an emergency). On one occasion, they had us testing reflective modulators used undersea (which take a signal in, modulate it, and reflect it back out the same port). So they were probably doing some optical FDM on top of exisiting commericial signals.
On another occasion we were debugging some OC-3 electronics that were flaking out undersea, due to the non-MilSpec components their vendor was using. So the obvious guess here is ATM. So I suspect that NSA runs a parasitic OC-3 ATM network optically "on top of" existing commericial OC-192. They can probably select up to 155 Meg of eavesdropped traffic to send into undersea AAL3 VCs and dredge back up over to be Echeloned.
(Of course, that OC-3 ATM network could merely have a been a control network for something far more complicated, which come to think of it might be more likely. I doubt they'd let us see so many components if it was possible to "guess" what their network was by seeing them.)
-TD
From: Thomas Shaddack <[EMAIL PROTECTED]>
To: Dave Emery <[EMAIL PROTECTED]>
CC: <[EMAIL PROTECTED]>
Subject: Re: Using time-domain reflectometry to detect tamper attempts on telecom cables
Date: Sat, 8 Mar 2003 07:39:36 +0100 (CET)
> But getting the bits from under the ocean somewhere back to > Fort Meade without being detected must be more interesting.
Can't they hire their own fiber in the cable, splice it, and feed the preprocessed data in there?
> It probably is true that the right wavelength laser will > penatrate water for some limited distance so a link could be set up from > a bouy near but below the surface to a sensitive telescope in earth > orbit.
I heard copper vapor lasers would do, that they are used for eg. intersubmarine communication. But can't confirm nor deny this.
> ...as there was no overlap of traffic on multiple wires.
What techniques are used to pick the data from the mix of the signals from the cables with more wires?
> Doing this for a sonet ring carrying 10 gbs or so as some > undersea cables now do seems rather challenging - at the very least > how one would follow changes in channel allocations and traffic loading > would seem very problematic. And intercepts that are weeks or months > old would be very much less interesting in most cases than near real > time intercepts - particularly of targets like terrorists.
It's being said that NSA is losing its grip on communications, to their great joy. It must make them mad. Hee! :) ...maybe the era is coming when even the US will be forced to play fair?
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