Show understanding of packet switching

Circuit Switching 📞

Think of a circuit switch as a dedicated phone line. When you call someone, a fixed path is reserved for the entire conversation. The line stays open until you hang up, and no other call can use that path at the same time. This guarantees a constant bandwidth but can waste resources if the line is idle.

• Dedicated path for the whole session.
• Low latency once the path is established.
• Resource‑intensive: unused capacity is wasted.
• Suitable for real‑time voice or video where delay matters.

Packet Switching 📦

Packet switching is like sending a parcel through a postal system. Your data is split into small packets, each with its own header (address, sequence number, etc.). Packets travel independently, possibly taking different routes, and are reassembled at the destination. This allows many users to share the same network links efficiently.

1. Data is divided into packets.
2. Each packet is routed independently.
3. Packets may arrive out of order; the receiver reorders them.
4. Network resources are shared, improving overall utilisation.

Key concept: Store‑and‑forward – a router holds a packet until it can forward it, ensuring reliable delivery. This process introduces a small delay, but the overall efficiency gains outweigh the cost.

Comparison Table

Exam Tips 🚀

• Define both circuit switching and packet switching clearly.
• Use a diagram to show a dedicated path vs. packet routes.
• Explain the store‑and‑forward mechanism in packet switching.
• Highlight the trade‑off between latency and bandwidth utilisation.
• Remember that packet switching allows dynamic routing and is the basis of the modern Internet.