Call blocking generates dispute between operators at Anatel A service that promises to block unwanted calls has generated a dispute between telephone operators: on the one hand, the defense that it protects consumers, on the other, the accusation that it prevents legitimate calls. The solution in question is "Vivo Anti-spam", automatically activated on new cell phone lines managed by the operator. According to the company, the service "identifies and blocks massive and fraudulent calls" before they reach customers. ?? Do you have any reporting suggestions? Send it to g1 But operators like TIM say the service prevents legitimate calls. At least seven companies questioned the blocking of thousands of calls, including health services for patients. They filed formal complaints with the National Telecommunications Agency (Anatel), which said it analyzed the cases and sought "sectoral balance and, above all, consumer well-being." Companies claim that Vivo's anti-spam system prevented legitimate calls Priscilla Du Preez/Unsplash TIM told Anatel that its users suffered undue restrictions, but refused to participate in a conciliation meeting. When contacted by g1, the operator stated that it will not comment on the matter. The main issue in the dispute between the companies is the criteria used to block calls, explained Eduardo Tude, president of the consultancy Teleco. "The phone's anti-spam works like that of e-mail: from time to time, things fall out that shouldn't have fallen. There is no perfect anti-spam that will only block what should be blocked", he stated. "Vivo cannot block legitimate calls. Anatel will have to establish some mechanism to prevent this from happening", he continued. Blocks affected public service The telephone company Adyl Telecom stated that, since the beginning of June, more than 16 thousand calls were interrupted due to anti-spam. The company claimed to Anatel that hospitals and public bodies were affected. The Vivo system was also accused of blocking calls from more than 800 numbers from Araçatuba city hall. The complaint was made by 3corp Technology, which provides telephone services for the city. In its representation, 3corp stated that the calls serve to provide public services in areas such as health, security and education, but were "systematically blocked or interrupted" by anti-spam. 23 thousand calls per second: Fantástico investigates how robots programmed to get you out of your mind work 3corp said that, in the first contacts, Vivo had not offered a viable solution to resolve the situation. But in July, the company stated that, after negotiations, the numbers were released and are fully operational. Adyl, in turn, complained about the lack of clarity regarding blocking criteria and said that, after contacting Vivo's wholesale channel, it managed to unblock most of the numbers. Net2Phone Brasil, another company questioning Vivo's anti-spam, said it expects a conciliation meeting mediated by Anatel. Agera Telecomunicações stated that, since the beginning of June, it has received complaints from customers about blocking calls to Vivo numbers and classified the anti-spam as a tool for "artificial traffic degradation". Unwanted automatic calls, called "robocalls" Fantastic Ateky Internet and Ágil Telecom also claim that the Vivo filter prevents legitimate calls made from their networks. g1 contacted the companies, but received no response until the publication of this report. Anatel informed that it opened space for Vivo's defense and that, since then, it has delved deeper into the materials presented by the companies. "The objective is to offer a coherent and replicable view across different cases," said the agency. Adyl and Agera told Anatel that Vivo's anti-spam system even blocked calls from numbers authenticated in the Verified Origin system, created to prevent unwanted calls. Verified Origin uses an international technology called STIR/SHAKEN. It checks, at the time of the call, whether the number used by the company is included in a register maintained by the operators. What Vivo says Although the complaints arose in June, Vivo said it has been offering the tool since November 2024. According to the operator, it protects customers from automatic calls that use doctored numbers to hide who is making the call. The company informed Anatel that the service went through an experimental phase with around 700,000 users before being expanded to its entire active number base. According to Vivo, its anti-spam works on two levels: first, it analyzes whether the call is authenticated or not, and then the profile of the originating number. In a note, the company claimed that it does not block calls that follow its anti-spam and STIR/SHAKEN rules. "Only companies that make massive and unidentified calls will be blocked." The operator also said that "it has been working hard to combat 'spoofing' [use of false numbers] that it receives via interconnection from other operators and that impacts its customers." Owners of numbers affected by the blocking can request an analysis through the Vivo website, and customers who do not receive calls can deactivate the service in the operator's application.