A report from Transaction Network Services (TNS) is praising the use of signed call traffic among the top carriers for progress made in robocall mitigation and maximizing the benefits of implementing STIR/SHAKEN.
Among these U.S. telecom carriers — AT&T, Charter, Comcast, Lumen, T-Mobile, UScellular, and Verizon — the report said 86% of all traffic was signed throughout the year in an effort aimed at the mitigation of unwanted robocalls.
The 2025 Robocall Investigation Report also affirmed that 95% of call traffic between those carriers was signed with “A-level” attestation. Establishing SIP-to-SIP connections between originating and terminating parties prevents the infiltration of malicious robocall activities on tier-1 networks.
“Top carriers deserve praise for their implementation of STIR/SHAKEN, which has enabled them to consistently sign traffic with high attestation levels,” Seth Walton, TNS’ general manager, of communications market, said.
However, it hasn’t stopped bad actors from launching unwanted robocall campaigns, Walton said. In fact, smaller carriers may have more difficulty implementing the right systems. Non-top carriers’ networks remain at serious risk, the report said.
“By fully modernizing and transforming SIP-to-SIP connectivity, the telecom industry will be in a stronger position to neutralize robocall threats and protect their subscribers,” he said.
The TNS report found that the percentage of signed calls between non-top carriers dropped by about 25% last year. Robocall bad actors have taken advantage of these providers’ reliance on legacy TDM circuits and the stripping of original STIR/SHAKEN data to obscure their malicious robocall traffic.
Insights from the robocall mitigation report that the broadband industry will want to watch:
- AI-generated robocalls will continue to make national headlines in 2025. Bad actors more frequently used AI-generated robocalls to exploit and defraud consumers.
- Political robocall volume soared in 2024. Top scams included fake voter registration, campaign donation requests, and misleading claims about how people could vote.
- The global rise of AI deepfakes presents challenges in combatting scams internationally, where scams have been noted in the United Kingdom, Australia, Slovakia, and India.
Robocalls remain a significant problem for carriers to address. Even though total robocall mitigation is in place and robocall volume in 2024 was at least 4% lower than in 2023, a recent YouMail report showed that it has hovered between 50 billion and 55 billion calls each year for the past four years.
