[kuschku]

> And yet you can't create your own small phone network, assign whatever numbers you want to your users, and expect others to interconnect with you or honor your numbers.

Actually you can quite easily, and quite a few people have done so. Including hacker clubs for events (the CCC operating a local custom GSM network with their own SIMs, and working numbers a few years back for their congress comes to mind), small ISPs with only a few hundred or thousand customers, and more.

It’s definitely possible, easy, and cheap.

[detaro]

I wouldn't call these event networks "part of the federated phone system". They are clients of companies that are part of it. External numbers into these networks are extensions of a public number they get from the upstream - just like any company having a PBX, they do not participate in any of the inter-provider infrastructure, do not own the phone numbers, ...

The internet equivalent to what they are doing would be getting a business line with a fixed, provider-owned IP prefix. The equivalent to what the parent describes would be getting a prefix delegation from a registry and peering with other networks.

It's still really cool for island systems though, which is the more important thing for those events.

[kuschku]

> I wouldn't call these event networks "part of the federated phone system". They are clients of companies that are part of it. External numbers into these networks are extensions of a public number they get from the upstream - just like any company having a PBX, they do not participate in any of the inter-provider infrastructure, do not own the phone numbers, ...

I mean, they ran their own full MVNO, with their own SIM cards, with their own code on the cards, and operated their own tower.

That isn’t a simple number.

[detaro]

I meant purely from a "connection to the general phone system" perspective - at all events I've been they only had internal numbers and you could be called from the outside through an extension. If there was an event where that wasn't the case I stand corrected.

Having the entire (mostly/entirely? open-source) GSM network is really really cool and important, but from the perspective of the wider phone network still "only" a "fancy internal phone system", with the limitations of control that come with that.