Alexander Graham Bell  patented the first Telephone instrument capable of practical use in 1876. This method was used in the first commercial instrument developed by Bell in 1876. In 1878, the first telephone exchange was established at New Haven. In 1880, two Telephone Companies viz. The Oriental Telephone Company Ltd. and The Anglo-Indian Telephone Company Ltd. approached the   Govt. of India for permission

to establish Telephone Exchanges in India. The permission was however refused on the grounds that the establishment of Telegraphs was a Government monopoly and that the Government itself would undertake the work in the event of sufficient demand. By 1881, Govt. of India changed their earlier decision and licence was granted to the original Oriental Telephone Company Limited of England for opening Telephone Exchanges at Calcutta, Bombay, Madras, Karachi and Ahmedabad.

28th January, 1882, is a Red Letter Day in the history of Telephone in India. On this day Major E. Baring, Member of the Governor General's Council declared open the Telephone Exchange in Calcutta, Madras and Bombay. The exchange at Calcutta named "Central Exchange" was opened at third floor of the building at 7, Council House Street. On 30-06-1882, the Central Telephone Exchange had 93 number of subscribers.

 A distant view of old Writers Building taken before the Dalhousie Institute was built within Dalhousie Square. The foundation of Dalhousie Institute was laid on 4th March 1865

                                                          On 1899, The Central Tele-   phone Exchange wsa shifted to   1, Council House Street. The   management of the Oriental   Telephone Company was   subsequently taken over by Bengal Telephone Company Limited. The telephone system in the city remained under management of Private Company till 1941 when all the shares of the Private company  were purchased by a Public Enterprise. The capital expen-   diture involved in this deal was   Rs 117 lakhs only. From 1st   April 1943, the control of the   Telephone system in Calcutta,Madras and Bombay was taken over directly by the

Indian Posts and Telegraphs Deptt. In 1985, Indian P & T was bifurcated and the control of Telephone has been transferred to Deptt. Of Telecom. On 01-10-2002, the telephone system of Calcutta came under Bharat Sanchar Nigam Limited (BSNL) alongwith all other circles except the city of Delhi and Mumbay which are under Mahanagar Telephone Nigam Limited (MTNL).

Dalhousie Institute Building - demolished on 1950  to make space for construction of Telephone Bhawan                                                                                         Calcutta Telephone District CTD) is the largest metro district of BSNL. Calcutta Telephones is having a service area of 1900 sq. k.m. covering the city of Kolkata and adjoining areas from five districts of West Bengal viz. Howrah, Hooghly, Nadia, North 24 Parganas and South 24 Parganas. At the time of Independence there were 20,000 phone connections in Kolkata. The figure rose to 5,00,000 by March 18, 1997 and crossed 1 million by February 27, 2000. CTD is the first metro network in the country to become fully electronic on 31-03-99 and is the first metro network in the country to become fully digital on 31-03-2000.

  Operators at Hare Street Manual Exchange - 1935

Today on 31-03-2003, CTD is  the most modern metro network of BSNL with about  13 lakh customers where telephone is available on demand, ISDN is available on demand and also leased circuit is available on demand.

During the last two years a large number of new technologies, new services and new customer care facilities have been introduced.

New Technologies and New Services

New technologies which have been introduced are

•   STM rings
  
  
•   Intelligent Network (IN) (first city to launch the service)
  
  
•   Local Network Managed System (first city to launch the technology)
  
  
•   Microtunnelling (first city to launch the technology)
  
  
•   Managed Leased Line Network (MLLN)
  
  
•   Wireless in Local Loop (WLL)
  
  
•   India Mobile Personal Communication Service (IMPCS)
  
  
•   Centrex
  
  
•   Answering Machine Service (AMS)
  
  
•   Fibre to the Building in the form of RLU and DLC which has reduced the average copper
    loop length to less than 2 K.M.
  
  
•   Direct Internet Access Service (DIAS)
  
  
•   Voice over IP (VOIP)
  
  
•   Account Less Internet
  
  
•   Internet Telephony (Webfone)
  
  
•   Sampark (IVRS based)
  
  

Customer Care Steps

•   Different modes of bill payment
  
  
•   Changed number enquiry service 1951/1952/1953
  
  
•   Billing information system 1501/1502/1503
  
  
•   Telephonic reconnection service
  
  
•   Telephonic address correction
  
  
•   Fault docketing through IVRS
  
  
•   CTD web site