[no_protocol]

I suppose they have even less incentive than internet service providers have to implement BCP 38 spoofing protection.

If it made business sense to do this, it would happen. Until then, it probably won't. Perhaps serving millions of robocalls are more profitable than the number of consumers who will totally cancel their telephone service as a result of them.

[howard941]

Pity there isn't a viable class action plaintiff's bar taking on the provider telcos to make the business case. Until then I'm doing what everyone else seems to be diong, blackholing calls pretending to be from my own exchange, and now trying a device on the landline to filter the ringing (a Lynx).