AT&T and T-Mobile announced a joint anti-robocall initiative today, but they have not promised any new call-blocking capabilities for their customers.
The carriers have made a big deal in the partnership, saying in an announcement that "they are putting up differences to combat unwanted robocalls for customers." Specifically, the companies said they are now using the new SHAKEN / STIR technology to determine if Caller ID numbers are disrupted by calls made between two carriers.
Theoretically, carriers can use Caller ID authentication technology to automatically block calls that fail authentication testing. But that's not the case right now. For example, AT&T told Ars that it uses Caller ID authentication as a data point in its anti-robocall algorithm but does not prevent calls only based on whether or not they are validated.
When a call is made between The AT&T and the T-Mobile network, a cell phone user may see a notification that the incoming call has been validated, meaning that it is coming from the number listed on the Caller ID field. But calls from phones do not fail the test, perhaps because the Caller ID is broken, customers' phones will still be called and may not come with a warning.
AT&T and T-Mobile both offer free blocking services, but both charge $ 4 a month extra for their more thorough blocking of services. No changes to the free or paid plans have been announced today.
"While validation does not solve the problem of unwanted robocalls itself, it is a major step towards giving customers more confidence and control over the calls they answer," AT&T said. of T-Mobile in their announcement.
The SHAKEN / STIR framework uses "digital certificates, based on common public key geographic methods, to ensure that a phone call is safe," telecom software provider TransNexus explains. "In simple terms, each telephone service provider obtains their digital certificate from a certificate authority that is trusted by other telephone service providers. The technology certificate allows the calling party to verify the number. the calling is accurate and not broken. "  As such, SHAKEN and STIR will work when adopted by all major telephone providers, and the Federal Communications Commission urges carriers to send them quickly. AT&T and Comcast announced that they completed a successful SHAKEN / STIR cross-network test in March.
Verizon said it started deployment of SHAKEN / STIR in March, and Sprint said it would do the same.
Broader industry required adoption
T-Mobile marked several calls as potential scams in incoming phone screen calls using previously implemented technology. But calls that failed the new Caller ID verification test won't come with warnings unless there's another reason to suspect it's a scam, T-Mobile told Ars. Most calls today are not subject to the SHAKEN / STIR test, T-Mobile said. Even after major US carriers implement SHAKEN / STIR, international calls and calls from small carriers may not be confirmed, the company said.
"This technology is still in its early days – the real benefit of the consumer is in the future, when most of your calls are Caller Verified and you notice those who are out of doubt," says T-Mobile.
AT&T told us that the SHAKEN / STIR status of the call was another access point added to other tests it was working to determine. if you block a call or issue warnings. Most legitimate calls today are not verified by SHAKEN / STIR, so the unverified status of a call is not enough for itself to trigger a block, AT&T said. "fraud." AT&T Call Protect also provides warnings for suspected "spam" calls but lets them ring your phone unless you buy a premium version for $ 4 a month and choose to automatically block this. AT&T says it calculates calls as spam if they appear to be disturbing but does not necessarily try to portray people.
New SHAKEN / STIR data is being fed to Call Protect, which already uses other data analytics and reports from customers to evaluate calls.
T-Mobile offers free robocall blocking but charges $ 4 a month for "Name ID." The paid service lets you block calls from specific callers or from across categories, "including telemarketers, numbers tagged as nuisance calls, political calls, survey calls and more, "T-Mobile said. The ID name is included for no extra cost with the $ 15-per-month T-Mobile One Plus add-on and T-Mobile's "Magenta Plus" premium plan but a separate $ 4 charges for other customers.