[mynameisvlad]

What, exactly, is difficult and expensive to maintain about a 555 number compared to any other?

Let's be real, we're all tech engineers here. Telephony backbones are all IP based now. It's all just mappings on a computer that routes your call to the right next hop. There's nothing at all special about maintaining one mapping vs another.

[mathgorges]

Iirc the article mentioned that 555 numbers used to be reserved for internal use, so my hypothesis is that implementing external 555 numbers likely required some sort of retrofit.

But I don’t have any domain knowledge here, so this is really just a guess

¯\_(ツ)_/¯

[iudqnolq]

> Telephony backbones are all IP based now. It's all just mappings on a computer that routes your call to the right next hop.

All I know about telecoms comes from Wikipedia, but that makes no sense. Why would the technology that determines where to route your call be related to the protocol used to transfer data long distances?

(Also the Verizon quote is from 2003.)

[mynameisvlad]

Telephony backbones are, for the most part, just SIP. When I say they’re IP based I mean they’re not old school POTS loops anymore.

It might have cost 2500 per area code when that was a requirement and you had to set these up loops up manually across longer distances, but nowadays it literally is just going to be a mapping in a computer, like any other.