Currently, there are about 32 active companies in this space, including Interregional TransitTelekom (MTT), Golden Telecom, TransTelekom and Synterra Media. share of fixed-line business of Rostelecom's main competitors varied in 2012 from 6% (Megafon) to 19% (MTS). Still, At the beginning of the 2010s, Rostelecom is de facto a monopoly local telephony provider to households in Russia, except for few regions, where incumbents were not part of Svyazinvest holding after the privatization in the early 1990s (the cities of Moscow, Pskov, Kostroma, the republics of Tatarstan, Bashkortostan, as well as Tuva, Chukotka, Chechnya, and Ingushetia). The substitution of long-distance fixed-line voice services by mobile and IP traffic sped up after 2008, when mobile operators shifted to the fixed-line segment (Vimpelcom was the first company out of the Big 3 to acquire Golden Telecom in early 2008) and simultaneously increased investments into own trunk network infrastructure to support rapid 3G traffic growth. In February 2014 Megafon, through its subsidiary NetByNet purchased Tele-MIG Besides a company founded in 2003 which provides fixed telephony, IP-telephony and data transmission in Yamalo-Nenets Autonomous Okrug. Russian regulation stipulates that new players must build their own networks. The growth of traffic between Europe and Asia is an additional opportunity; more than 6,000 km of international communication cables were built during the first nine months of 2007, representing a 48.5% increase on 2006, according to the Russian Ministry of Communication and Mass Media. Tariffs Tariffs in the fixed-line segment are determined by the Federal Tariff Service on an annual basis, taking into consideration inflation and the operators' expenses. The price competition in the long-distance segment increased as mobile operators began implementing promotional tariffs to stimulate voice traffic growth after the crisis (long-distance traffic is predominantly built by corporate clients). At the same time, traditional operators had limited room for maneuver as intra-zonal and domestic LD tariffs, which are subject to regulation by the government, remained flat over the last three years. As a result, mobile operators managed to bite off a heavy share of intraregional and long-distance market from traditional fixed-line operators, first of all regional operators of Svyazinvest, which are now united under Rostelecom. Public switched telephone network Russian public switched telephone network (PSTN) has specific features. The lowest part of this model is example of the local network in the middle and large cities. The central office (CO) is connected to the tandem exchange (TE). In