Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Falsehoods Programmers Believe About Phone Numbers (2016)

github.com

Post reply on HN
Print view View original

101–110 of 209 posts

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#101

Post by ranma42 »

distantaidenn wrote: post #72
segfaultbuserr wrote: post #16

I have/had a Facebook account with a phone number. The account was left unused for a few years. Recently, I used my E-mail to reset its password, unfortunately, since the account was abandoned for a long time, the system flagged my activity as "suspicious" automatically, and asks me for confirmation using my phone number. But I no longer own that number. And from the customer Q&A forum, I realized I was not the only…

Storytime: I bounce between Japan and Korea for work. I was in Seoul for about a year and a half and naturally had a Korean phone number. I used this number to sign up for Line (a popular chat service in the two countries), and I also linked my email address to the account. So when it was time to move back to Japan, I naturally canceled my Korean phone service. Fast forward 6 months, and my Line account suddenly disa…

Looks like I got lucky, I ran into this where a while after moving a switched to a new phone and couldn't activate line because I didn't have the old number anymore. However I managed to sort it out with the line customer service (even though some of the questions like "when did you first register your line account" I could only guestimate because it was so long ago).

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#102

Post by PakG1 »

A lot of people have horror stories about what happens when they lose their phone number, etc. Concern can be extended to email address. I agree that it's a valid concern, there needs to be a better way to handle this. I am surprised that this happens with this crowd though. I would figure this crowd would update all their relevant stuff when their information changes. I normally do. But I know that definitely this would still be a problem for ordinary laypeople, so I'm not trying to blame the victim, and so I'm not sure what my point is. I guess this is just not an easy problem. I imagine identity theft would be rampant if the processes and requirements were more relaxed. I don't know what the solution is. :(

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#103

Post by FabHK »

"Every phone number has an area code."

Is the falsehood of the above statement sufficiently evident? I don't see it listed explicitly. In Hong Kong, for example, phone numbers are just 8 digits (+852 1234 5678). Some websites/apps insist on an area code, forcing one to arbitrarily split the number.

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#104

Post by Tor3 »

nitwit005 wrote: post #11

> An individual has only one phone number Always feel these lists include things no human actually believes.

>> An individual has only one phone number

> Always feel these lists include things no human actually believes.

Well, somebody believes that. I can register my phone number with the local postal system, and, as shippers add a phone number to shipments, I can search for shipments to me by logging in to my post company account on the net, or via the Android app. The problem? I can only register a single phone number. But I have two numbers, and, for various reasons, different shippers must sometimes use one or the other, and not the same number. But I can't register more than one, and I can't register two accounts - b/c they also need my social security number, which is unique. So I can only track a subset of shipments to me. All because somebody there (it's their own software) made the assumption that an individual can only have, or at least use, a single phone number. I did report this as a bug, with no understanding.

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#105

Post by JdeBP »

I would, from personal experience, construct a quite different list. Some of mine would be:

* Every other country's telephone numbering is like one's own.

* Every other country's telephone numbering is like that of EU countries, or like the NANP.

* The last 10 digits are the subscriber number.

* Geographic numbers are actually geographic.

* 123456789 is a perfectly fine number to use for test calls.

* STD is exactly like NPA-NXX.

* The leading 1- in NANP long distance form is the country code.

* There are only national and international forms nowadays.

* Users do not use E.164 themselves.

* Emergency numbers are easy to filter out, as it's only one number.

There are also falsehoods that people believe about telephones, which I would start with:

* When you hear the ringing tone, the other end is already ringing.

* Your ringing tone comes from the other end.

* Every network sends in-band call progress tones.

* It's perfectly fine to use fax over a G.729 'phone.

* DTMF is in-band and universally supported.

* DTMF is out of band and synchronous to media.

* There is only one way that callees reject calls, and it never involves being connected.

* TPC does not need to know the correct physical location of your non-mobile 'phone.

* TPC tracks mobile 'phones through "a GPS chip".

* Calls can only be traced whilst the caller is on the line.

* Caller-ID is unspoofable and works across networks and across countries.

* The callee can always clear calls.

* Only the caller can clear a call.

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#107

Post by Tor3 »

AnaniasAnanas wrote: post #22
wongarsu wrote: post #14

Earlier quoted context omitted.

As long as you don't try to validate the email address I entered. The list of gotchas for email address parsing is impressive too. (e.g. "Cool Address"@example.store is a valid email)

These might be valid but nobody uses them and nobody will complain if you do not support them.

But, you know, I have seen one or two such email addresses. So somebody do use them.

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#108

Post by apk17 »

ThePadawan wrote: post #79

Between 2004 and 2007, Zurich (Switzerland) also switched dialing prefixes such that multiple phone numbers in fact referred to the same extension [0]. [0] Wikipedia unfortunately has the description only in German: https://de.wikipedia.org/wiki/Ehemalige_Telefonvorwahl_(Schw...

Kleinwalsertag. Austrian territory, but only reachable (by road) through germany. Was connected to german phone network, which changed once telco stuff got smart enough. Effect: For some time a german and an austrian phone number reached the same phone.

Re: Falsehoods Programmers Believe About Phone Numbers (2016)

#110

Post by scbrg »

duskwuff wrote: post #31
AnaniasAnanas wrote: post #22

Earlier quoted context omitted.

These might be valid but nobody uses them and nobody will complain if you do not support them.

Not sure why this is getting downvoted. It's a valid point. There is a gap between "technically valid email addresses" and "email addresses that reasonable people use".

Not that I downvoted, but the attitude annoys me. As a developer you have two options:

1) Do nothing and support all valid addresses (that your mail system can handle)

2) Spend development time to make your system not support all valid addresses.

Why do you spend development effort to make your software worse?

Post reply on HN