AT&T plans towork with Comcastto curbrobo calls. Thephoneand cable giants are joining forces for a new service that will giveconsumersthemeans to authenticate calls that are made between networks.

The system will let a user verify incoming calls not just from within a single providers network but also from other participating providers. Selected consumers already are testing the filtering system.

AT&T says thetest calls are being authenticated and verified using the SHAKEN/STIR protocol. It is the first time such call verification is being carried out between providers using SHAKEN/STIR.