FR version is available. Content is displayed in original English for accuracy.
Advertisement
Advertisement
⚡ Community Insights
Discussion Sentiment
40% Positive
Analyzed from 3744 words in the discussion.
Trending Topics
#fiber#backup#system#same#going#don#where#faa#cable#actually
Discussion (99 Comments)Read Original on HackerNews
>A man stranded in the bush in northern Saskatchewan was rescued last week after chopping down four power poles — knocking out electricity to surrounding communities. [...]
>But he had an axe and he knew SaskPower would have to check the downed line, so he went to work.
Pretty grim that a life critical system wasn't designed to report that the backup fibre was unserviceable until they attempted to switch over to it.
I wonder how long it was down? Days, weeks, months?
I am paying, $1000, $1800 & $1900 for the same service at 3 different location (20 mins from each other).
Two locations, I also have old coax lines that are still active, but not paying for it.
When I bought two businesses, I learned that they were paying for a dedicated fiber but using coax service.
At one of the location, we had fiber, and paying for backup coax and wireless. But if you turn off fiber box, it wont fail over to either one.
I wouldn't surprise it was down for weeks and no one bothered about it.
For a major trans-oceanic backbone provider, at least 15ish years ago they had a mile or two between Detroit and Chicago where both ends were on the same side of the interstate highway.
But it's more frequent on DAS (Distributed Antenna Systems, AKA small-cell or micro-cell) networks.
Also the challenge of when fibers are leased (if that's still a thing, based on the networks I helped design I'd say 'probably').
They really are analogous to Lamport's "Distributed System" quip; A damaged fiber owned by a company you have never heard of can wreck your day.
For mission critical stuff like airports I would like to think they're go for a more rigorous methodology than hope for the best on paths
Usually it’s a combo of a tier 1 that decides that a resell agreement is “good enough” and “well just eat the loss” and then by the time stuff like this rolls around “we’ll get back to you” + a bunch of silly explanations that boil down to “you’re not gonna sue us though” start coming out lol
Luckily we were on Century Link so weren't affected by his stupidity. lol
Over ten years ago, my employer was spinning up a new DC across the state and had three links between it and the primary DC. Two were pretty direct, but we needed a third because at one point in the 300 mile path, the two main links went within 400 meters of each other.
So how national-security-adjacent critical systems like an airport system doesn't have a larger set of backup links, and validates that they are geographically separate up until the connections, and have realtime alerting on the connection status, is surprising to me.
This isn't relevant in this case. The problems occurred at different places. The backup fiber was, separately from the issues with the primary system, cut by a construction crew. It's not two fiber lines both cut at the same spot.
Recently, I tried calling 811 before digging in my yard. The webpage was broken and the hotline kept me on hold forever. I gave up. Small wonder.
https://blackhydrovac.com/underground-utility-strikes-learn-...
You're going to be hard-pressed to find any point in the American empire's life when it doesn't have 'current tensions' with someone or other.
Similar events happened in Europe disguised as thieves stealing fiber optic. This does not have any sense economically, as the value in the market is zero so... either is an honest accident and is cleared in a few days, or is sabotage
Do you honestly think that crackheads think that far in advance?
I've seen fiberoptic cables stolen from 2 (city) jobsites in the last 5 years, once by tweakers later caught trying to sell them as scrap copper and the second thief was never caught. This happened even though the spools had big signs on them saying "Fiber Optic Cable - NO COPPER".
I worked for a regional ISP that had a major outage when the redundant fiber provided by the telephone company was cut in one place triggering a full loss of connectivity. It also caused a massive 911 outage for 200,000 people as it isolated the 911 center from the city core.
Turns out the phone company didn't connect one side of the ring topology even though they certified they did. Needless to say lawsuits abounded.
The amount of shit I was given everytime I went through a checklist working at a fedramp certified company working with emergency alerts on the phone system made me prematurely gray.
I could feel the barely contained seething rage everytime I told the execs that the reason this release will take 3 days and not be instantaneous like your friends releases at a faang and that information made you embarrassed at your dinner party, is because you agreed to this process contractually years ago and now it’s a crime if I just sign off on it being ok without actually checking that it’s ok.
A lot of people are incompetent.
There's generally two wrong responses: (1) We spent a lot of money on 'blah blah blah', a lot of other companies use it, so yeah, we've got a backup/failure system. And, (2) inadequate testing - either, we tested 1 of 50 services, and it worked, so the whole system can be restored; or, we gracefully tested, and it worked, so it will obviously work during not-graceful incidents.
And the root cause of this is generally that no one gets promoted for implementing an adequate backup/failure system, or it's extremely rare.
Not saying that's what is going on here, just that it's possible.
Sometimes the level of incompetence / lack of care in organizations like this astounds me. I understand issues like this can be complicated and systemic but it honestly makes me think very poorly of the technologists building these systems in government.
Nothing I've ever seen or experienced with FAA indicates a lack of care; the parsimonious explanation is almost always that people who care a great deal are working within complex systems that don't always have a consistent or externally legible set of priorities. Or more intuitively, the failures we see are the "acceptable" ones versus the unacceptable ones (like planes falling out of the sky).
Hard to fathom someone still holding that view after the 737MAX disasters.
The NTSB has repeatedly and publicly criticized the FAA for failing to implement their recommendations, including as recently as last week (Amazon Prime crash resulting in 5 deaths). They've explicitly called out the FAA's failure to act as a contributing factor in crashes, multiple times.
Regulatory capture ruined the FAA.
BT guy ends that part of the presentation with "the IRA will really have to get shit together to take you off the net"
This was during the troubles. Same planet, different world.
https://www.airwaysmag.com/new-post/faa-smart-first-deployme...
The fundamental problem with DCA, and one of the two main causes of the crash [1], is that they are required by political pressure to operate at a higher operational tempo than they can safely operate at. DCA has essentially 1½ usable runaways--large planes can only use the larger runway, and given the capacity restrictions, airlines have been pushing to use fewer small planes at the airport. This shift in plane size means the effective safe slot capacity has gone down, but people still keep citing the same number as justification for safe numbers, and the politicization of the issue has shut down everyone who complained that the actual traffic just couldn't be safely handled.
If DCA's theoretical slot capacity (36 landings and takeoffs each per hour) is to be reached one just one runway, you have about 100 seconds to go from plane 1 touchdown; exit the runway, letting plane 2 on to take off; plane 2's wheel leaving the runway, clearing plane 3 touchdown. That's doable, but with essentially 0 margin for error. Alternating the runways used for each landing would give you closer to 30s of margin, but if only 10-20% of the planes can use the alternate runway, you can't divert enough planes to use the alternate runway.
Now DCA and the FAA aren't stupid enough to actually schedule 36 landing slots every hour, but the problem is that because of a few various factors, what was scheduled as, say, 30 slots for an hour (giving 120 seconds between landings, probably sufficient margin) ends up being 12 slots used in the first half-hour and 18 slots used in the second half-hour, which means a lot of the actual operation ends up having no safety margin even though on paper you have sufficient margin.
One of the ways you can rectify that is to assign slots further in advance so that you don't get the bunching. Effectively saying "oh, if you leave right now, you'll arrive at 3:30 with three other planes, but if I hold you for 10 minutes, I can push you into a less busy arrival time." Doing this requires good, accurate prediction of the actual flight travel times, and my understanding is that this is what the new software is meant to provide.
[1] The other main cause is essentially that the DoD's aviation practices in the area is a giant clusterfuck that endangers lives, and unfortunately that sentence is not relegated to the past tense.
Good luck to all of us.
The government politicians who approved this are frequent flyers out of there, so they’re at least getting their lives out on the line before the rest of the country if it proves ill managed or conceived.
It’s basically dogfooding.
one day the backbone (E1 bidirectional ring iirc) was broken north of london … my boss drove out to find that travellers had entered the field, opened the inspection cover in the ground, stood a pole for their clothes line and filled with cement
very savvy, he didn’t let on that we had about £1m revenue per day close to collapse and convinced them to hang their clothes somewhere else (perhaps a few quid changed hands)
Or is it that these ATC networks are their own air-gapped network with less redundancy? That just doesn't add up. Or maybe there was only one line going to the ATC, with no multiple "ISPs" like a datacenter would have?
* There is supposed to be a primary and a secondary link, in this case the primary failed and the fail-over also failed. It's unclear from the reporting if they were damaged in the same incident or if the failover was not tested or monitored adequately.
The Philadelphia TRACON site has been notoriously unreliable and was supposedly improved in 2025, it's also unclear if these issue actually could stem from that implementation.
First big oops of this form that I remember:
"In December 1986, the ARPANET had 7 dedicated trunk lines between NY and Boston, except that they all went through the same conduit -- which was accidentally cut by a backhoe. "
https://www.csl.sri.com/~neumann/insiderisks06.html
In any system where both sides of redundancy always carry traffic then loss of one link can cause congestion failure if any link fails. This is a very common means of failure in electrical networks that requires load shedding. Well, you can't load shed air traffic.
A more complex system that I like, but comes with it's own set of constraints and implementation issues is a system where both lines carry all the traffic at all times. This way the default state of the system is always working and your first failure isn't invisibly critical.
But this is very hard as we see in TCP when things get out of order and high latency creeps in. You have to manage a lot more state at the data level.
That seems like an extremely foolhardy thing to do.
It seems like it would present a less-chaotic solution than that provided by having no data communications at all.
(The actual easiest method is to install the conduit or direct burial cable with tracer wire)
Before fiber a lot of things were put into the ground with no thought how you would find it again.
I sometimes hire directional boring and excavation contractors and if there’s any doubt as to where an electrical conduit or natural gas pipe is, I opt for the hydrovac truck to minimize risk.
And of course there are marker posts that say "buried fiber optic cable do not dig".
Most cheap hired labor doesn't realize you shouldn't dig up the market posts and throw them in the dumpster on construction sites. Add a little bit of rain and suddenly the contractor showing up with an excavator that was told everything was properly marked, and can see markings in other places but not where they are digging, and disaster occurs.
Also soils aren't static, I've been on sites where the midpoint of a buried telecommunications cable had drifted over 8 feet from where the markers were a few hundred yards apart. Just looking at the markers and assuming a straight line isn't a safe bet. Looking at the fence rows to the left and right of the cable and you could see a matching bow in the fence rows.
[QUOTE:]
Russia has been staging covert operations and deniable provocations against European countries for many years. Since its full-scale invasion of Ukraine began in 2022 they have increased. These have included incursions by reconnaissance drones, hacking, arson, parcel bombs targeting cargo flights and plots to kill executives of leading European arms firms. In recent months the pace of such shadowy attacks appears to have risen again. The Russian operations have three main goals, according to analysts and security officials: trying to coerce European countries into halting their support for Ukraine; raising the costs of providing that support; and attempting to make NATO look powerless.
[/QUOTE]
And of course there've been "suspicious" cable cuts in the Baltic Sea and other European waters ....
https://www.economist.com/europe/2026/09/21/russias-grey-zon...
"Hybrid warfare" "Grey-zone attacks"
Our media, utilizing only the finest establishment euphemisms.
In places like these, it's not the best contractor that wins, but the one that supports genocide against Palestinians.
https://www.cnn.com/2025/02/25/business/musk-faa-starlink-co...
right. of course, no ones going to cut corners on the safe use of AI and secure infrastructure in this administration.
With low-enough engineering quality, you don't actually need saboteurs.
While I agree, that’s just what they told us. Not sure I believe it anymore. The fact the first UK one happened immediately after they sanctioned Israel is also just a big coincidence.
Just sayin
Press X for doubt.
[1] https://www.npr.org/2026/09/21/nx-s1-5976816/faa-ai-manage-a...