AT&T and T-Mobile have started rolling out call verification technology for calls between the two networks. Soon, if a phone call is made from one network to another using a compatible device, the recipient sees a message & # 39; Caller verified & # 39; and they know for sure that the conversation does not come from a fake robocall or spammer. AT&T also says it is testing the integration of the data used by this system, its Call Protect service, which it began offering to its customers for free last month.
The rollout is the final step in the struggle of US mobile providers to stop robocalls, and it is after Ajit Pai, president of the Federal Communications Commission, ordered them to implement a call verification system by the end of 2019. Last month, the FCC criticized what it called Carriers are making slow progress towards this goal after it had voted to allow carriers to block robocalls as early as June.
T-Mobile and AT & T & # 39; s call verification partnership is based on the SHAKEN / STIR standard, which can check whether a caller ID is correct. T-Mobile was the first to implement the standard for calls within its network in January and in March, AT&T and Comcast announced that they were working together to authenticate calls between their two networks. This was followed by a similar announcement from T-Mobile and Comcast in April. Sprint has said it plans to test the technology on its network in the second half of this year.
The SHAKEN / STIR standard has its limitations – namely that it can only see when a call is absolutely legitimate, rather than knowing when it is absolutely spam – but as more devices and network providers implement the standard, the ratio of verified to Unauthenticated calls increase, increasing the chance that an unauthenticated call is spam and can be safely ignored.