Carriers are sabotaging Voice Talk, Kakao says

Kakao, operator of the nation’s most popular mobile messenger KakaoTalk, seems headed on a full-on collision course with local mobile carriers as Kakao CEO Lee Sir-goo claimed yesterday they are manipulating their networks to drag down the quality of KakaoTalk’s voice calls.

At a forum in Yeouido, western Seoul, he said Kakao has been keeping track of the percentage of users’ voice data that fails to reach the interlocutor ? known as the “loss ratio” ? since June 4, when Voice Chat was launched in the country on a trial basis.

The first day showed a loss ratio of 0 to 1 percent, meaning near perfect voice call quality, but it abruptly deteriorated from the third day, he said. The larger the figure is, the harder it becomes for callers to understand each other. “Carriers must have hampered the network,” he said.

The daily fluctuations of the loss ratio are shown in the form of a weather chart on Kakao’s main blog, which can viewed at blog.kakao.com. This shows how the loss ratio rose as high as 20.3 percent for calls made on SK Telecom’s network, up from 1.1 percent on the first day.

From Saturday, the same ratio on KT’s network climbed up to 14.8 percent. The chart also showed how the ratio skyrocketed to 51 percent from June 6 on the network of LG U+, the nation’s No. 3 carrier. It did not drop back down even after the company announced it would scrap restrictions on all mobile voice over Internet protocol (mVoIP) services regardless of how much its subscribers pay per month.

Mobile carriers have been criticizing Kakao, which has over 35 million subscribers in Korea, for freeloading on their networks since the new Voice Talk service became available on cellular networks.

Lee expressed concern that mobile service operators may raise their monthly charges using Voice Talk as a pretext as only users who pay monthly fees in excess of 54,000 won ($46) are allowed to use the free mVoIP.

But the carriers made different claims. SK Telecom said Kakao has misinterpreted and misrepresented the statistics because the 10 to 20 percent loss rate was calculated by including users who pay less than 54,000 won a month and are blocked from using the mVoIP service.

The problem arises from the fact that it took a day or two for the carrier to interpret the data traffic from the new voice call service to enforce the restriction on them, said a spokesman with SK Telecom.

“We are pretty sure Kakao knows about this but is deliberately hiding the truth to make it seem like carriers have some nefarious intentions, which is regrettable,” he said.

By Seo Ji-eun[spring@joongang.co.kr]