JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III Year COMPUTER NETWORKS Previous Question Paper (March - 2021 - R13/R15)

The TCP/IP reference model is a four-layer architecture designed for the ARPANET. The layers are:

1. Application Layer: Handles high-level protocols like HTTP, SMTP, and FTP, allowing user processes to communicate.
2. Transport Layer: Manages end-to-end communication using TCP (connection-oriented) or UDP (connectionless).
3. Internet Layer: Uses the IP protocol to route packets across multiple networks using logical addressing.
4. Network Access Layer (Host-to-Network): Interfaces with the physical hardware to transmit data frames over the medium.

Comparison with OSI model:

Fiber optic cables transmit data as pulses of light through a glass or plastic core. Advantages include:

• High Bandwidth: Supports significantly higher data rates than copper cables.
• Low Attenuation: Signals can travel longer distances without needing repeaters.
• Immunity to Interference: Being dielectric, they are immune to electromagnetic interference (EMI) and crosstalk.
• Security: Extremely difficult to tap into without detection.

Functionalities:

1. Light Transmission: Uses Total Internal Reflection (TIR) to guide light through the core.
2. Signal Modulation: Converts electrical signals into optical pulses via lasers or LEDs.
3. Signal Regeneration: Uses optical amplifiers to boost signal strength over long-haul links.
4. Demodulation: Photodetectors at the receiver convert light pulses back into electrical signals.

The structure consists of a core (inner light-carrying medium), cladding (refractive index lower than the core to ensure TIR), buffer coating (protection), and an outer jacket.