ISDN is a digital telephone service that can transmit voice, data and control information over an existing single telephone line. What is the full form of ISDN?

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RRB NTPC CBT 2 (Level-3) Official Paper (Held On: 14 June 2022 Shift 2)
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  1. Integrated Server Digital Network
  2. Integrated Services Digital Network
  3. Integrated Services Diversified Network
  4. Interpreted Services Digital Network

Answer (Detailed Solution Below)

Option 2 : Integrated Services Digital Network
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The correct answer is Integrated Services Digital Network.

Key Points

  • ISDN is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network.
  • This results in potentially better voice or data quality than an analog phone can provide.
  • It provides a packet-switched connection for data in increments of 64 kilobit/s.
  • It provided a maximum of 128 kbit/s bandwidth in both upstream and downstream directions.
  • A greater data rate was achieved through channel bonding.
  • It can integrate speech and data on the same lines, which were not available in the classic telephone system.

Additional Information

  • Advantages of ISDN:
    • ISDN channels have a reliable connection.
    • ISDN is used to facilitate the user with multiple digital channels. 
    • It has a faster data transfer rate.
  • Disadvantages of ISDN:
    • ISDN lines are costlier than the other telephone system.
    • It requires specialized digital devices.
    • It is less flexible.
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