Re: Wrong tree
"Personally I'd give subscribers the choice between rejecting dubious calls with fine-grained controls, with the caveat that they may be barring legit traffic at their own risk, or continuing with the broken-arsed mess in case they need the old "features.""
The same people you'd be asking to set those controls are the same ones willingly handing over bank details on the phone. Is suspect their level of technological sophistication is low.
"Of course, none of this disproves my original assertion that it is the broken-arsed mess that is the core of the problem "
Indeed. The signalling protocols were developed and agreed in the days before deregulation and before anyone with a SIP server and some internet connectivity could set up as a telco. There was a degree of trust involved between the parties, who were largely state-owned at the time. I don't think that anyone predicted at the time that there could be a 'rogue telco'.
I think the point stands though that it's not possible for one single telco, or even one single country's telcos, to fix this on their own. I think where we might end up is the former PTTs building 'trusted' international links between themselves and smaller, newer, telcos being excluded from that. If a call originates on one of those networks the CLI will be trusted and shown, if it doesn't "Unavailable". There'll be plenty of unintended consequences though - sign up with a cheap telco in a country, or use Skype or similar services, and your international calls won't get through anymore.