[mattrp]

As someone who has been involved in telco routing / call infrastructure, I agree and disagree. Most telcos hate that their networks are being flogged by these short duration calls. When they have the engineering competence / business ethics / operational focus in place, solutions emerge and have been around for awhile. You won’t get them all but simple heuristics that’s others have described above will squash the big abusers. The problem is these spam artists, prey on the fact that like the old internet of twenty years ago, a bad actor could relatively easily exploit weaker networks. Like most things I expect the first 80% of this problem will get resolved pretty quickly and then we will see some sort of vendor driven standards that become available / implemented within the next year.

Edit: I think one interim solution could be a dcma-style process whereby carriers prove to the fcc that they maintain an auditable takedown process that can be initiated by the consumer and that the carrier is applying reasonable technological solutions to minimize / detect en masse robocalls.