T-Mobile and Comcast have formed a partnership to fight robocalls. Both companies will use the STIR/SHAKEN protocol to help customers with call verification. Unfortunately, to get the “Caller Verified” label, only calls between the two networks are eligible.
The new feature to fight robocalls is available to T-Mobile and Metro by T-Mobile customers. You must have certain Samsung and LG devices to be eligible for the service. On Comcast, the service is available to Xfinity Voice home phone service customers starting later this year. There's currently no word if this feature will be included in Comcast's Xfinity Mobile service. T-Mobile also added that it plans to bring the feature to more smartphones in the near future.
Both companies claim that they are the first to deliver this robocaller protection across networks. However, several others are not far behind. AT&T and Comcast have been testing the protocol across their networks, and Verizon is working to bring STIR/SHAKEN protocol to calls made in-network. This tech may not stop robocalls, it will make it easier to spot them.