Multiple subsea fiber cuts in the Red Sea impacting global communications
Impact Summary
Starting at 05:45 UTC on 06 September 2025, traffic traversing through the Middle East originating and/or terminating in Asia or Europe regions may experience increased latency due to multiple undersea fiber cuts in the Red Sea. The disruption has required rerouting through alternate paths which may lead to higher-than-normal latencies.
This advisory is intended to raise awareness ahead of increased demand as the regions enter the start of its work week.
Current Status
Multiple international subsea cables were cut in the Red Sea. Our engineering teams are actively managing the interruption via diverse capacity and traffic rerouting, while also discussing alternate capacity options and providers in the region.
Undersea fiber cuts can take time to repair, as such we will continuously monitor, rebalance, and optimize routing to reduce customer impact in the meantime. We’ll continue to provide daily updates, or sooner if conditions change.
This message was last updated at 19:30 UTC on 06 September 2025
cr125rider · 3h ago
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.
movedx · 2h ago
BGP <3
marcosdumay · 1h ago
Yes, but it's damn time people start upgrading to BGP ==3.
> "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 dispatched. "All these vessels are strategically placed around the world to be 10-12 days from base to port,"
...
> To repair the damage, the ship deploys a grapnel, or grappling hook, to lift and snip the cable, pulling one loose end up to the surface and reeling it in across the bow with large, motorised drums. The damaged section is then winched into an internal room and analysed for a fault, repaired, tested by sending a signal back to land from the boat, sealed and then attached to a buoy while the process is repeated on the other end of the cable.
adolph · 11m ago
I wonder how much slack is left in the cable over its run in order to facilitate bringing it up for repair.
soupfordummies · 56s ago
Now that’s what i call a service loop!
typpilol · 3h ago
Were they cut on purpose or accident?
betaby · 2h ago
Cables in Red Sea got cut frequently. All the time it's the same story - anchor dropped where it should not. Similar stories happen near Singapore.
mandeepj · 2h ago
> Cables in Red Sea got cut frequently
On land, we’ve call before you dig. I wish they could do something like call before you drop (anchor) training or just get the word out.
jvilalta · 2h ago
They are usually marked on nautical charts.
anikom15 · 2h ago
(It’s not actually anchors.)
bmelton · 42m ago
It very often _is_ an anchor, and they are usually dropped and dragged on purpose for the effect of cutting the cables which are clearly marked on charts as places to not drop anchor
gpm · 1h ago
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.
viraptor · 2h ago
It's only been a few hours. I doubt anyone knows.
MengerSponge · 30m ago
Every subsea cable service interruption story is an excuse to share one of my favorite pieces of long-form technical history: Neal Stephenson's Mother Earth Mother Board:
Can they splice these? Surely the don't have to run a whole new cable?
staplung · 17m ago
They can but it's an involved process. Modern cables manage their slack very precisely - a complicated job in and of itself - and usually cannot be hauled to the surface without snapping them. So if the cable is not already cut (an anchor can damage a cable in a variety of ways short of physically snapping it) it will be cut while still on the bottom. The ends are then winched up and a splice is patched in but now there's a rather lengthy section of extra cable to deal with. They deal with that by laying it down precisely on the seabed in a nice sideways loop.
to11mtm · 1h ago
I've only done land based fiber design, but I would assume based on my experience in that field that one of two things happens.
First option, there's some slack somewhere nearby to do a pull nearby.
If you ever pay attention to aerial poles, you'll see at various intervals things that are vaguely reminiscent of a snowshoe or tennis racket, in the industry they are in fact informally referred to as a 'snowshoe' and the entire purpose is to have some fiber to 'release' if a cut happens and a resplice is needed. [0]
I'd -assume- there is an analogue for these in undersea cables...
If not, well then you'd have to splice a length in and probably have the right sort of mechanism to ensure the cladding/etc stays contiguous (maybe even weld? IDK) but regardless you're probably talking... Actually wait yeah they've got this all figured out; https://www.youtube.com/watch?v=QiwidMEv8CM
[0] - Real world example, for instance if someone uses a fiber splice can for target practice.
Waterluvian · 1h ago
I think they raise the cable to the surface, splice it and sink it again.
bigiain · 6m ago
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 more difficult...
> To repair the damage, the ship deploys a grapnel, or grappling hook, to lift and snip the cable, pulling one loose end up to the surface and reeling it in across the bow with large, motorised drums. The damaged section is then winched into an internal room and analysed for a fault, repaired, tested by sending a signal back to land from the boat, sealed and then attached to a buoy while the process is repeated on the other end of the cable.
Impact Summary
Starting at 05:45 UTC on 06 September 2025, traffic traversing through the Middle East originating and/or terminating in Asia or Europe regions may experience increased latency due to multiple undersea fiber cuts in the Red Sea. The disruption has required rerouting through alternate paths which may lead to higher-than-normal latencies.
This advisory is intended to raise awareness ahead of increased demand as the regions enter the start of its work week.
Current Status
Multiple international subsea cables were cut in the Red Sea. Our engineering teams are actively managing the interruption via diverse capacity and traffic rerouting, while also discussing alternate capacity options and providers in the region.
Undersea fiber cuts can take time to repair, as such we will continuously monitor, rebalance, and optimize routing to reduce customer impact in the meantime. We’ll continue to provide daily updates, or sooner if conditions change.
This message was last updated at 19:30 UTC on 06 September 2025
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 dispatched. "All these vessels are strategically placed around the world to be 10-12 days from base to port,"
...
> To repair the damage, the ship deploys a grapnel, or grappling hook, to lift and snip the cable, pulling one loose end up to the surface and reeling it in across the bow with large, motorised drums. The damaged section is then winched into an internal room and analysed for a fault, repaired, tested by sending a signal back to land from the boat, sealed and then attached to a buoy while the process is repeated on the other end of the cable.
On land, we’ve call before you dig. I wish they could do something like call before you drop (anchor) training or just get the word out.
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.
https://www.wired.com/1996/12/ffglass/
https://news.ycombinator.com/item?id=20497098
https://web.archive.org/web/20210107003422/https://www.wired...
The Verge also has a great article which is more recent and more specifically about a repair ship:
https://web.archive.org/web/20240422050805/https://www.theve...
First option, there's some slack somewhere nearby to do a pull nearby.
If you ever pay attention to aerial poles, you'll see at various intervals things that are vaguely reminiscent of a snowshoe or tennis racket, in the industry they are in fact informally referred to as a 'snowshoe' and the entire purpose is to have some fiber to 'release' if a cut happens and a resplice is needed. [0]
I'd -assume- there is an analogue for these in undersea cables...
If not, well then you'd have to splice a length in and probably have the right sort of mechanism to ensure the cladding/etc stays contiguous (maybe even weld? IDK) but regardless you're probably talking... Actually wait yeah they've got this all figured out; https://www.youtube.com/watch?v=QiwidMEv8CM
[0] - Real world example, for instance if someone uses a fiber splice can for target practice.
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 more difficult...
An article about such repairs (150-200 yearly)
> To repair the damage, the ship deploys a grapnel, or grappling hook, to lift and snip the cable, pulling one loose end up to the surface and reeling it in across the bow with large, motorised drums. The damaged section is then winched into an internal room and analysed for a fault, repaired, tested by sending a signal back to land from the boat, sealed and then attached to a buoy while the process is repeated on the other end of the cable.