Date: Sun, 10 Feb 2008 21:14:02 -0600> From: measl@mfn.org> To: DaveHowe@gmx.co.uk> CC: cypherpunks@al-qaeda.net> Subject: Re: undersea cable cuts> > On Sun, 10 Feb 2008, Dave Howe wrote:> > > Tyler Durden wrote:> > > Tapping an underwater cable is far, far harder, but the NSA is known by> > > fiber> > > guys to have at least two of the very expensive and very specialized subs> > > necessary.> > > > I was under the impression that there were regeneration nodes every so many> > tends of KM (essentially receiver/emitter pairs, with a bit of logic in the> > middle to reshape the
No real ruminations are needed on these subjects: They're known and by no means secret. Regenerators are mostly gone now, both on land and undersea, replaced by the optical fiber amplifier. Undersea cables carry electrical power through a lining in their sheeth. An OTDR can't see past a traditional regenerator: The fiber span is terminated. (It also can't see past an optical fiber amplifier because of the isolators that keep the ASE from lasing inside the amplifier.) Tapping an optical fiber is absolutely trivial, more trivial than tapping a (copper) cable carrying an electrical signal. This isn't inside inside knowledge, even the guys in the trucks know it. Tapping an undersea optical cable, however, is a completely different matter, and it's VERY difficult, though routinely done by NSA, etc... Undersea cables do occasionally break, but the net-quoted statistic of approximately 12 breaks at any one time throughout the world is entirely misleading: There are millions of route-miles spanning the Atlantic, the Pacific and everywhere else. This means that the odds of three or four breaks in a small area are practically zero. They are designed to be extremely resilient, and this design choice has been quite successful. A simple anchor (even from a large ship) is not in general going to cut a cable. -TD pulses to keep them clean) > > On land, yes. At sea? To be honest, I never really considered it... > Thinking about it though, my guess would be no. I base that on several > things:> > (a) The location of the break is determined via OTDR. How can you know > where your reflection originates if you have regen stations?> > (b) Power requirements are very significant at regens: where does all this > happy juice come from at the floor of the sea?> > (c) Regen stations would introduce elevated failure rates that are not > seen (by me. YMMV).> > > and always assumed at least> > some of those were equipped with additional logic to allow a suitably equipped> > sub to simply clamp an inductive coil around the node and "ask" the node to> > emit signal in EM form so the sub could listen in... > > I find this hard to buy into for all of the above, *plus* the difficulty > of shoving multiple fibers through such an inductive device. I simply > dont believe it possible.> > > how many of the bundled> > fibres you could that for in parallel would be a design issue though, albeit a> > minor one (using a clamp-on coil surrounding the entire node, you could pretty> > much use the entire radio spectrum as bandwidth and assign one frequency per> > repeater; I suspect you would need to supply power inductively too though,> > given the power requirements for an "active" node of this time would go though> > the roof compared to normal operation.)> > Exactly. Even if they try to multiplex on top of themselves, there just > no way.> > As has been pointed out by many (even myself I think), these breaks are > clearly an organized event, but of unknown purpose. as was astutely > pointed out, the guys who would want to do the cutting are separate from > and antithetical to, the guys who want to do the monitoring. Also, the > guys who want to do the monitoring dont need to be breaking cables to do > it - they bring out the Jimmy Carter (now that her sister is truly > mothballed) and they do it in a nice dry lab on the ocean floor, with a > good cup of hot coffe fresh from nuclear irradiation (er, "heating").> > I see no point to these acts, but neither can I deny that these acts > *must* have been deliberate. And I do not pretend to know what everyone > else could possibly be considering as motives. I do particularly like the > hypothesis put forward about testing the responses of places nobody > otherwise cares about, but thats just the shit disturber in me, I'm sure > ;-)> > //Alif> > --> Yours,> J.A. Terranson> sysadmin_at_mfn.org> 0xBD4A95BF> > > What religion, please tell me, tells you as a follower of that religion> to occupy another country and kill its people? Please tell me. Does> Christianity tell its followers to do that? Judaism, for that matter?> Islam, for that matter? What prophet tells you to send 160,000 troops> to another country, kill men, women, and children? You just can't wear> your religion on your sleeve or just go to church. You should be> truthfully religious.> > Mahmoud Ahmadinejad _________________________________________________________________ Helping your favorite cause is as easy as instant messaging. You IM, we give. http://im.live.com/Messenger/IM/Home/?source=text_hotmail_join