the permanent back office of the World Bank, which is one of the largest buildings owned by the bank outside its headquarters in Washington, DC. The Chennai office handles corporate financial, accounting, administrative and IT services of the bank, in addition to several value-added operations of the bank that were earlier handled only in its Washington, DC office, including the bank's analytical work in bond valuation which is estimated to be US$100 billion. Several foreign banks have established their branches in the city. The first Sri Lankan Bank in India was established when the Bank of Ceylon opened its branch in Madras on 31 October 1995. Infrastructure Communication Chennai is one of four Indian cities connected to the rest of the world by undersea fibre-optic cables, the other three being Mumbai, Kochi, and Tuticorin. The city is the landing point of major submarine telecommunication cable networks such as SMW4 (connecting India with Western Europe, Middle East and Southeast Asia), i2i (connecting India with Singapore), TIC (connecting India with Singapore), BBG (connecting India with the Sultanate of Oman, Malaysia, the UAE, and Sri Lanka), Gulf Bridge International, and BRICS (connecting India with Brazil, Russia, China and South Africa). The 3,175-km-long, 8-fiber-paired i2i has the world's largest design capacity of 8.4 terabits per second. Work to lay a 2,300-km undersea optical submarine cable connecting Andaman and Nicobar Islands to mainland India through Chennai, carrying 100 Gbit/s optical waves, is slated to begin in December 2019 and completed by March 2020. It will connect Port Blair and the islands of Havelock, Little Andaman (Hutbay), Car Nicobar, Kamorta, Great Nicobar, Long Island and Rangat with Indian mainland. , eight mobile phone service companies operate seven GSM networks including Airtel, Aircel, BSNL, Vodafone, Tata Docomo GSM, Idea, Reliance GSM and three CDMA networks including MTS, Reliance CDMA, Tata Docomo CDMA in the city. 2G Mobile internet connections are provided by all the operators, and 3G and 4G mobile broadband are provided by few operators in the city. There are four land line companies providing commercial and domestic broadband Internet services. Chennai was the first Indian city to deploy Wi-Fi internet access in a widespread manner. , there were 9.8 million mobile phone users in Chennai. In 2010, Chennai had the fourth highest number of active Internet users in India, with 2.2 million users. As of 2018, the city topped in broadband speed among Indian cities,