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Airlines are running out of 4-digit flight numbers

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Re: Airlines are running out of 4-digit flight numbers

#281

Post by anoncow »

jll29 wrote: post #227

> Here’s the full answer, along with how they triage the problem – for instance by assigning the same flight number to more than one flight a day (although that means they need for it to be flights that would never both be in the air at the same time, such as where the same plane is used and can’t reasonably be substituted) This sounds like it's calling for trouble! Whenever I hear that any IDs could be "recycled", I…

>Whenever I hear that any IDs could be "recycled", I make a mental note to replace the person making such a proposal from all teams that I am involved in.

Mental note to not work for you.

Re: Airlines are running out of 4-digit flight numbers

#282

Post by Cthulhu_ »

gentle wrote: post #83

I love that so many people here think they can think about the problem for 10 seconds and come up with a solution that hasn't already been considered a thousand times and discarded.

Obviously, the solution is a blockchain and matching cryptocurrency where miners can generate flight IDs which the operators can then buy off of an exchange. I've already pre-mined all convenient and vanity flight IDs for a smooth launch, each ID will be sold at an automated blockchain auction with prices starting at $1000 each. IDs cannot be reused.

Re: Airlines are running out of 4-digit flight numbers

#283

Post by rand_r »

vel0city wrote: post #256
cobbzilla wrote: post #247

Earlier quoted context omitted.

Have you ever changed the static IP address of a computer? You just “recycled” a “globally unique” ID. Recycling unique IDs (more precisely: changing the underlying thing the ID points to) is not impossible; there’s lots of pathological failure modes; for certain ID-spaces it’s kinda a required use case; so we have to deal with it.

IP addresses (especially IPv4) are not even supposed to be globally unique. How many 192.168.1.1 devices are out there? How many different distinct physical boxes respond to traffic going to 1.1.1.1?

Because of NAT, it’s actually “IP + Port#” that is globally unique, and ultimately associated with a single physical network interface on a device (e.g an ethernet port on a PC).

There’s exceptions like broadcast IPs, but the point is that it is a system for uniquely locating devices and listening OS processes with IDs routinely shifting around.

Re: Airlines are running out of 4-digit flight numbers

#284

Post by indus »

In 2010, Indian railways switched from a four-digit numbering system to five digits.

They were running out of train numbers.

Indian railways today operates 13,000 trains daily.

There is a PDF that talks about the problem, the solution, exceptions, and a rollout plan.

One fine day, IT systems seamlessly transitioned—-took some time to wipe the old numbers from passengers memories.

Re: Airlines are running out of 4-digit flight numbers

#285

Post by nottorp »

belorn wrote: post #279
nottorp wrote: post #241

Earlier quoted context omitted.

Do you understand on what basis? Do you know enough to assign addresses in a way that you, not your router, wants? Can you ssh/other forms of remote into any machine that accepts ssh on your local network using only ipv6? Can you redirect ports to specific local machines using only ipv6 (that implies they keep constant addresses)? Can you easily switch between two internet connections going through different routers…

Do not "ssh/other forms of remote" using ip addresses. Use domain names or local domain. It is easier to remember, is more secure (if configured in DNS), and less prone to errors. > Can you redirect ports to specific local machines using only ipv6 (that implies they keep constant addresses)? Yes. Use domain names in configuration files. It more robust, easier to read, and is better protected against network changes o…

> It is easier to remember

I have absolutely no problem remembering the last byte of any machine on my network. Because that's all it takes with ipv4 on a sorta complex home network, no need for extra services.

> Are you talking about BGP?

No, with ipv4 i can just change the default route :)

Everything is NATed behind the two routers so changing the default route changes which connection that machine uses. You're thinking enterprise, and then ipv6 becomes ... fine. I just have a hack that works fine for me.

Re: Airlines are running out of 4-digit flight numbers

#286

Post by [deleted] »

thaumasiotes wrote: post #173
davchana wrote: post #142

Earlier quoted context omitted.

> Airport boards are conveniently sorted by departure time. Not true always. Often I see them sorted alphabetically by Destination, then time (in west coast US). Or occasionally (in middle east) by Airline Name & then Time. All Qatar Airlines together. Sometimes even whole LCD Labeled (digitally, on screen) as A-E, F-M etc. and a bit frustrating way, because often I know my flight destination, but not precise time (&…

> Not true always Except that you go on to describe boards being sorted by time? They may also sort by destination or airline, which are the other pieces of information that I noted passengers already know. You can't use an airport without knowing your departure time and airline, and while it's technically possible to use the airport without knowing your destination (sort of... in point of fact, whenever I check in,…

[deleted]

Re: Airlines are running out of 4-digit flight numbers

#287

Post by nottorp »

vel0city wrote: post #263
nottorp wrote: post #241

Earlier quoted context omitted.

Do you understand on what basis? Do you know enough to assign addresses in a way that you, not your router, wants? Can you ssh/other forms of remote into any machine that accepts ssh on your local network using only ipv6? Can you redirect ports to specific local machines using only ipv6 (that implies they keep constant addresses)? Can you easily switch between two internet connections going through different routers…

> Do you know enough to assign addresses in a way that you, not your router, wants? If I want to manually assign addresses it's still pretty simple, but in the end I normally just don't care. I don't want to know what IP my printer is, I just want to reach it. Which isn't a challenge at all. Even for things at my home that are IPv4 only they're practically all DHCP. Because there's little reason to ever really care a…

> as mine only took me an hour or so while yours took multiple days.

Yeah, because the first time I had no idea what I was doing, except vague feelings about ipv4 works. Did you factor in your pre existing ipv6 knowledge when you counted just an hour?

> Network Prefix Translation can be done pretty easily.

What's "easily"? How many services do I need to setup? Some other helpful HNer tried to explain to me once and the list was like 2 or 3 daemons in addition to dhcp, firewall etc.

Do you set up complex ipv6 networks at work?

Re: Airlines are running out of 4-digit flight numbers

#288

Post by vel0city »

rand_r wrote: post #283
vel0city wrote: post #256

Earlier quoted context omitted.

IP addresses (especially IPv4) are not even supposed to be globally unique. How many 192.168.1.1 devices are out there? How many different distinct physical boxes respond to traffic going to 1.1.1.1?

Because of NAT, it’s actually “IP + Port#” that is globally unique, and ultimately associated with a single physical network interface on a device (e.g an ethernet port on a PC). There’s exceptions like broadcast IPs, but the point is that it is a system for uniquely locating devices and listening OS processes with IDs routinely shifting around.

> it’s actually “IP + Port#” that is globally unique

So which globally unique box is 192.168.1.1:443? Can you point to exactly one device out there with that IP:PORT combo? There's probably hundreds of millions of that IP:Port combination currently running and listening.

Which globally unique box is 8.8.8.8:53? You think there's seriously just one network adapter listening for traffic at 1.1.1.1:53? These aren't "broadcast IPs".

https://en.wikipedia.org/wiki/Broadcast_address

And even then, "ultimately associated with a single physical network interface on a device" isn't correct either. You can have multiple physical interfaces listening on the same IP and end up with the same ports.

https://en.wikipedia.org/wiki/Link_aggregation

Re: Airlines are running out of 4-digit flight numbers

#289

Post by kqr »

eknkc wrote: post #235
jll29 wrote: post #227

> Here’s the full answer, along with how they triage the problem – for instance by assigning the same flight number to more than one flight a day (although that means they need for it to be flights that would never both be in the air at the same time, such as where the same plane is used and can’t reasonably be substituted) This sounds like it's calling for trouble! Whenever I hear that any IDs could be "recycled", I…

Hey they are inventing NAT. Nice.

Wait, how are they doing that? My mental idea of NAT is that it dyanmically links (address × port) pairs to local addresses. What would be the "port" in the case of flight numbers?

Re: Airlines are running out of 4-digit flight numbers

#290

Post by josephcsible »

> assigning the same flight number to more than one flight a day (although that means they need for it to be flights that would never both be in the air at the same time, such as where the same plane is used and can’t reasonably be substituted)

I thought this was already common on a lot of airlines. For example, tomorrow, Southwest flight 1861 goes from MDW to DAL from 1:55pm to 4:10pm, then from DAL to SNA from 4:50pm to 5:55pm, then from SNA to PHX from 6:30pm to 7:50pm. I was on two legs of a similar flight a few years ago, and I didn't even have to get off the plane at Love Field.

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