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Comment by lordnacho | Hacker News Reader

I've rented some of these lines as part of a financial trading infrastructure.

What's immediately obvious is the line is much faster than going over the public internet, and there's no jitter: every time you ping it comes back in the same amount of time, whereas the internet pings will vary by several ms.

You also become acutely aware of cable breaks. Somehow this happens quite often under the English Channel. The network operator will start sending you emails that say

- Cable break detected

- Loading ship (can take ages)

- Found the break

- Patched it

- Back up

Occasionally bad weather would delay it.

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>You also become acutely aware of cable breaks. Somehow this happens quite often under the English Channel.

You're not lying. :) When the internet is down in the ROI (Republic of Ireland), it's always because something was dragging along the seabed and cut the cable[s].

Given that the ROI doesn't have many IX's for international connection[0,1,2], it's quite hard to miss when it does happen.

[0] - https://en.wikipedia.org/wiki/Internet_Neutral_Exchange

[1] - https://www.inex.ie/technical/network-diagram/

[2] - https://www.submarinecablemap.com/#/country/ireland

I had always had the illusion that Ireland was well connected to US and EU. Given how many tech company have Data Centre in there. Quite Strange its IX isn't as good as it could be.

Off Topic:

Is the short form (Republic of Ireland) ROI used often? Because the first thing that springs to mind reading ROI is Return of Investment.

Isn't Ireland short enough as a word? I understand there is Northern Ireland, but people will actually put Northern In front of it to be specific. Like North Korea instead of Korea.

ROI is often used, yes.

It's a good way of easily differentiating between whether you're talking about Ireland the island, or Ireland the country, which currently excludes the six counties of Northern Ireland (NI) which are still part of the UK.

The term Ireland is often used to refer to the island as a whole, but obviously this can depend on the political leaning of who you're talking to.

Northern Ireland, depending on context and/or who is speaking can otherwise be referred to as Ulster (problematic, as the province of Ulster has 9 counties, only 6 of which are in Northern Ireland). It is also common in some circles to refer to the 6 counties currently occupied by the British simply as "the north".

In short, Ireland is a hot geopolitical mess and when talking about Ireland, it is useful to be as specific and as neutral as is possible.

So ROI/NI are quite useful shorthands.

I strongly suspect most residents of Northern Ireland would take umbrage at the word "occupied"

> The five most recent opinion polls taken in the North show similar results, with support for the North staying in the UK ranging from 45 per cent to 55 per cent, and averaging around the 50 per cent mark. [0]

Way closer than you think. (Using desire for a united Ireland as a proxy here)

[0] https://www.irishtimes.com/opinion/polls-suggest-gradual-shi...

You're not wrong. There is a loyalist majority in NI. But those that would refer to Northern Ireland as "the north" would generally be among those that definitely would refer to the six counties as occupied.

To explain ROI you really wouldn't had to use terms like 'still part of UK' and, as mentioned, 'ocuppied'. This only distracts.

> Is the short form (Republic of Ireland) ROI used often?

Most often usages for me are filling out forms and that's often the shorthand representation next to the soccer team's score during a match.

> Is the short form (Republic of Ireland) ROI used often?

It disambiguates the polity from the island, which includes both the Republic and a sometimes problematic piece of the United Kingdom.

Ireland is the same length as America, which people often abbreviate to USA or US. This also cuts the confusion of America's multiple potential meanings (North/South continents, etc).

Its a touchy and pedantic subject. 95% of people will understand what you mean when you say "Ireland", the last 5% will want to start a flame war over it because reasons.

It's easy to remain oblivious and treat any mention as pedantry when you're not among those affected. Even if 95% of people are like that, denying their reality is still a form of soft bigotry. Here's an essay that might help to explain why some people care more than you do, and rightly so.

https://www.nytimes.com/2018/10/18/opinion/england-ireland-b...

I understand what you're saying, but it's not just pedantry.

You do have to be specific about what you mean when you say "Ireland" in any context where it is important that you are understood.

"Ireland" can quite correctly either mean the island of Ireland or the country called Ireland (aka The Republic of Ireland). In a political or business context you are likely to be specifically referencing one or the other.

I think in this context (cables landing on an Island called Ireland) we're ok to use simple terms and be understood.

That wasn't the question ksec asked though was it.

"Off Topic: Is the short form (Republic of Ireland) ROI used often?"

But also no. Cables landing in ROI would be under completely different regulatory control to cables landing in NI which would be under United Kingdom regulatory control.

In the context of Internet connections "Ireland" is precise enough, since either normal meaning works.

Since they're geopolitically separate and have their own infrastructures, the distinction is quite apt for understanding the "who" of who is impacted when the specific cables are cut.

In other words, based on your assumption that "Ireland" is precise enough and since Belfast (NI) has it's own IX, that would mean that you would have dichotomy where "Ireland" could connect to the internet and "Ireland" could not, yeah?

Agree, it's like saying Europe. If you ask a geologist, it will include Russia. If you ask Macron, it will not!

Sort of like how people confuse The Republic of China (ROC) with the People's Republic of China (PRC)?

No doubt there are a great many other parallel situations out there. My dental hygienist took issue with the Netherlands being called Holland.

>"I've rented some of these lines as part of a financial trading infrastructure."

Unless you were lighting that fiber yourself you were renting wavelengths and not the physical fiber.

>"What's immediately obvious is the line is much faster than going over the public internet, and there's no jitter: every time you ping it comes back in the same amount of time, whereas the internet pings will vary by several ms"

Jitter is caused by congestion which happens at router interfaces. The absence of jitter is not due to the use of dedicated submarine fiber spans per se as the speed of light in fiber is a constant. What you are likely seeing is the result of a network operator who has optimized for low and consistent latency by having fewer hops in their network before and after the cable landing stations.

Yeah that's right, I guess it could read like them being underwater matters. Point was that being private and optimised made the jitter go away.

How costly is such renting?

You're unlikely to rent the whole thing so it just depends on how much bandwidth you need. If it's only a couple of TB per month it's not that expensive.

Maybe it is expensive. They could be seeing "trading" and charge more because those folks have deeper pockets. Like how the DLSR industry is suddenly charging astronomical prices when the feature set of their devices is for cinematographers.

Edit: Why the downvotes? Adjusting the price to how much the customer is ready to pay instead of just offering the cheapest possible price is usual business practice.

But that doesn't answer actually how expensive.

It depends on what you want. Starts at maybe a couple of thousand bucks a month I would guess, I haven't looked for the cheapest in the market. Depends on the link and availability and so on.

You pay per capacity, not per data transmitted

One thing I’ve consistently noticed is that a “network” can tell the tale of natural or man-made disasters in terms of how it first manifests in alarms and breakage in various systems, the human response manifested to respond to it (sometimes across many national boundaries), culminating with the sometimes peculiar “hacks” and temporary solutions conjured up to restore connectivity. The network sees everything and no one ever tells these stories in any meaningful detail.

General purpose computers networks and software are far from optimal for high speed trading. A few years back ACM Communications published a comprehensive white paper of trading communications bottlenecks including the effect of virtual memory page faults and TCP/IP collisions. Dedicated trade networks want custom software without virtualization features. Or if you dont want to develop that much, use the ancient real time UNIX NASA has in its space probes like VxWorks.

In a few weeks there is annindie film called The Hummingbird Project about avrace between firms to build the fastest dedicated trading line.

The book Flash Boys by Michael Lewis covers HFT in general and a similar fiber optic line built by Spread Networks in 2010. It's definitely a fascinating world.

Apparently HFT's have moved on to microwave (https://www.bloomberg.com/news/features/2019-03-08/the-gazil...) to gain a further edge over fiber optic.

>Somehow this happens quite often under the English Channel.

How often? Once or twice a year?

And what were the reason it breaking so often? I thought the English Channel were quite free of Cargo Ships and the like.

> I thought the English Channel were quite free of Cargo Ships and the like.

The English Channel is the busiest shipping lane in the world: https://www.youtube.com/watch?v=pzJwXxUY3MM

Lived near Brighton for years and had never knew that! I stand corrected.

> I thought the English Channel were quite free of

Very much not:

http://www.guinnessworldrecords.com/world-records/busiest-sh... (1999)

https://www.marineinsight.com/marine-navigation/the-strait-o... (2017)

There is some discussion to be had as to whether there are other sections of water that are more active and have been for some years, but even if the channel isn't the busiest it is certainly very busy.

http://www.bognorregisbeach.co.uk/live-shipping-map-english-...

:-)

-Educated guess is that cargo vessels aren't much of a problem. Anything dropping anchor, dredging or somehow doing stuff on the bottom, on the other hand...

Further, I'd wager that initially buried cable in the Channel often is exposed on the bottom due to strong currents, rendering it more vulnerable - but this is just a guess, mind.

I think more than twice a year when I was renting it.

I'd be very curious what the timelines between each step looks like.. any insight?

Everyone knows immediately when the line is down, and which line it is.

If the ship is ready it seems to take a day or so to get to the site. There's not always a ship though, not sure how it's organized.

Another day at the site and it's done. But any weather blows up the schedule seemingly.

I've never received anything other than emails about this so I'm not actually an expert.

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