Hacker News Reader

Comment by jimbobthrowawy | Hacker News Reader

I have heard of people calling emergency numbers to test if a phone is working, but never a country making that impossible. Here, I had always assumed that repeated nuisance callers would be investigated to see if there's an actual problem, and charged with a crime if they're doing it for no good reason.

Always thought it would make more sense to have a dedicated "test number" for this purpose. Probably with some rate limiting.

View on HN

A lot of telcos used to have phone numbers you could call that would just say the number you're calling from (like with a computerized voice). I forget what this was called, but it was talked about in phreaking community or so on. Not sure if these "caller identifier" phone numbers are still around today though.

They're easier to make than ever, all you need is Twillio and a bit of Python code. There are quite a few in the US alone, both provided by carriers as well as enthusiasts and other companies in the industry.

They're called ANACs - automatic number announcement circuits.

Ah yeah that's right, thanks!

800-444-4444 still works. Even starts with "thank you for calling MCI"

BT in the UK has 17070 which tells you the number and lets you do tests like the "quiet line test". Handy when working out what was going on when I moved into a property with no live phone service (so no normal outgoing calls), lots of phone extension sockets, and (I discovered) two landlines coming in...

Reply on news.ycombinator.com