WBJECA 2025 — Computer PYQ

A Network Switch is a hardware device that connects devices within a Local Area Network (LAN). It operates at Layer 2 (Data Link Layer) of the OSI model, making it capable of filtering and forwarding frames based on Media Access Control (MAC) addresses.

The primary function of a switch is to ensure efficient communication between $n$ connected devices. If we consider the throughput $T$ of a switch, it is designed to manage multiple simultaneous conversations such that the total capacity utilized is:

$$Tota{l}_{Throughput}=\sum _{i=1}^{n}Capacit{y}_i$$

Unlike a hub, which broadcasts data to all ports, a switch reduces unnecessary traffic by creating a temporary, dedicated path between the source and destination ports. The efficiency of data transmission ($E$) can be defined as the ratio of successful frame delivery to total frames sent:

$$E=\frac{Frame{s}_{delivered}}{Frame{s}_{sent}}$$

• Router: Operates at the Network Layer (Layer 3) to route packets between different networks.

• Gateway: Operates at various layers, primarily to connect networks using different protocols.

• Modem: Operates at the Physical Layer to convert analog signals to digital and vice versa.