Packet Switching

Packet switching is a method of transmitting data over a network. Unlike circuit switching, which establishes a dedicated connection between sender and receiver, packet switching breaks data down into small units called packets. These packets are then transmitted independently across the network and reassembled at the destination.

How Packet Switching Works

1. Data Segmentation: The sending device divides the data into packets. Each packet contains a portion of the original data and a header.
2. Packet Header: The header includes information such as the source and destination addresses, sequence number (to ensure correct reassembly), and error detection codes.
3. Routing: Packets are routed independently through the network. Each router examines the destination address in the packet header and forwards the packet to the next hop.
4. Transmission: Packets are transmitted across the network via various links (e.g., telephone lines, fiber optic cables, wireless).
5. Reassembly: At the destination, the packets are received. Using the sequence numbers in the headers, the receiving device reassembles the packets into the original data.

Key Components

• Sender: The device that breaks the data into packets.
• Packets: The units of data transmitted over the network.
• Routers: Devices that forward packets based on their destination addresses.
• Receiver: The device that reassembles the packets into the original data.

Advantages of Packet Switching

• Efficient Use of Network Resources: Multiple users can share the same network links simultaneously.
• Robustness: If one route is unavailable, packets can be rerouted through alternative paths.
• Flexibility: Can handle varying data volumes and types.
• Cost-Effective: Generally cheaper than circuit switching, especially for bursty data traffic.

Disadvantages of Packet Switching

• Delay: Packets may experience varying delays due to network congestion and routing decisions.
• Complexity: Requires more complex network infrastructure and protocols.
• Potential for Packet Loss: Packets can be lost due to network errors or congestion. Error detection and correction mechanisms are used to mitigate this.

Feature	Circuit Switching	Packet Switching
Connection	Dedicated connection established	No dedicated connection; packets routed independently
Resource Usage	Dedicated resources during the connection	Shared resources; more efficient use
Delay	Consistent delay	Variable delay
Robustness	Less robust; single point of failure	More robust; packets can be rerouted

Figure: Suggested diagram: A diagram illustrating data being divided into packets, each with a header containing source and destination addresses, and being routed independently through a network to the destination, where they are reassembled.