AT&T and Comcast say theyve hit new milestone in fight against robocalls One way wireless carriers are working to stop the flood of unwanted robocalls is through authentication systems that verify caller IDs. One drawback so far has been that these systems work only on calls to and from the same provider. On Wednesday, AT&T and Comcast said theyll offer call authentication between networks later this year. Customers will be able to see verified calls from all participating carrier providers. AT&T and Comcasts authentication system is the industrys first to verify calls between separate providers, according to the companies release. The two carriers verified calls earlier this month between AT&Ts Phone digital home service and Comcasts Xfinity Voice home phone service, the companies said in the release. "While authentication wont solve the problem of unwanted robocalls by itself," the companies said, "its a key step toward giving customers greater confidence and control over the calls they receive."This comes after the Federal Communications Commission said carrier companies need to implement robust call authentication systems this year. In February, FCC Chairman Ajit Pai said companies should get the systems installed by the end of 2019 or the FCC will consider "regulatory intervention."