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Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

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Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#32
post #28

Earlier quoted context omitted.

I think they raise the cable to the surface, splice it and sink it again.

I've read (or perhaps watched on YouTube) the same thing. Finding both ends of the cable to grab abd raise it took longer than the raise/splice operation. I suspect a sufficiently malicious attacker could intentionally cut the cable twice, so when the repair crew drag up one end of the cut they know about, the section between the cuts drags its other end away from it's cut-point making the second repair significantly…

Cutting twice wouldn't be an issue, they can send a signal from both ends to get a reflection of how much of the cable is dead.

Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#33
post #28

Earlier quoted context omitted.

I think they raise the cable to the surface, splice it and sink it again.

I've read (or perhaps watched on YouTube) the same thing. Finding both ends of the cable to grab abd raise it took longer than the raise/splice operation. I suspect a sufficiently malicious attacker could intentionally cut the cable twice, so when the repair crew drag up one end of the cut they know about, the section between the cuts drags its other end away from it's cut-point making the second repair significantly…

In most cases they can easily figure out approximately where the break is on the line by simply measuring the resistance in the cable's conductors (they have more than one but the big one caries a 10,000V feed to power the repeaters). A double cut would probably show up as resistances that didn't sum to the proper total.

Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#34
post #19

Earlier quoted context omitted.

(It’s not actually anchors.)

Why do you say that? I can't say I'm an expert on the matter, but my understanding from industry reporting on some likely intentional ones in the Baltic where that they were still unambiguously done with anchors. Just by someone intentionally causing the anchor to drop and drag along.

It's by far the most common.. but.. Multiple cables in this manner is IME /less/ likely to be an anchor, although it has happened.

Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#35
post #28

Earlier quoted context omitted.

I've read (or perhaps watched on YouTube) the same thing. Finding both ends of the cable to grab abd raise it took longer than the raise/splice operation. I suspect a sufficiently malicious attacker could intentionally cut the cable twice, so when the repair crew drag up one end of the cut they know about, the section between the cuts drags its other end away from it's cut-point making the second repair significantly…

In most cases they can easily figure out approximately where the break is on the line by simply measuring the resistance in the cable's conductors (they have more than one but the big one caries a 10,000V feed to power the repeaters). A double cut would probably show up as resistances that didn't sum to the proper total.

You can only practically do that optically e.g through OTDR. You can't TDR steel conductors exposed to the ocean 500KM away with a ohm meter and a Murray loop, to even have a chance you need to put low voltage on it and it's not even close to as accurate.

Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#37
post #14

Earlier quoted context omitted.

The smart folks who keep these things running, despite failures like this, are incredible. Hats off to you all, good luck in the coming weeks as you have to deal with this.

BGP <3

Most likely not. Almost certainly bfd or ldp/mpls

Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#38

Earlier quoted context omitted.

The smart folks who keep these things running, despite failures like this, are incredible. Hats off to you all, good luck in the coming weeks as you have to deal with this.

https://www.bbc.com/future/article/20241014-the-deep-sea-eme... An article about people who fix this Also, the teams are quite busy: > "There are 150 to 200 instances of damage to the global network each year. So if we look at that against 1.4 million km, that's not very many, and for the most part, when this damage happens, it can be repaired relatively quickly." ... > If a fault is found, a repair ship is dispatche…

> 1.4 million km

Strange way of writing 1.4gm.

Re: Microsoft Azure: "Multiple international subsea cables were cut in the Red Sea"

#40
post #19

Earlier quoted context omitted.

(It’s not actually anchors.)

Why do you say that? I can't say I'm an expert on the matter, but my understanding from industry reporting on some likely intentional ones in the Baltic where that they were still unambiguously done with anchors. Just by someone intentionally causing the anchor to drop and drag along.

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