---
title: "Packet vs message switching"
subject: "Data Communication"
chapter: 7
key: "semester_5/data_communication:packet-vs-message-switching"
source: https://www.bctengineer.com/q/semester_5/data_communication/packet-vs-message-switching
site: BCT Engineering
---

# Packet vs message switching

Data Communication · Chapter 7: Switching

- Asked in: 2078 Bhadra, 4 marks
- Video: [Switching Techniques in Computer Networks](https://www.youtube.com/watch?v=-HlJ4psu5aU) — Neso Academy
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/data_communication/packet-vs-message-switching
- Whole chapter: https://www.bctengineer.com/md/semester_5/data_communication/chapter-7

## Question

Write a short note on packet switching versus message switching.

## Short answer

Message switching sends the entire message as a unit stored at each node, causing high delay. Packet switching divides the message into small packets, using pipelining to reduce delay. Packets share links fairly; only damaged packets are retransmitted. Packet switching suits real-time traffic better.

## Answer

Both use **store-and-forward** switching in which no dedicated path is reserved, but they differ in the unit that is sent.

- **Message switching:** the entire message is sent as one unit from node to node. Each node receives the whole message, stores it (often on disk) and forwards it when the next link is free.
- **Packet switching:** the message is divided into small packets of limited size which travel independently (or along a virtual circuit) and are reassembled at the destination.

| Point | Message switching | Packet switching |
|---|---|---|
| Unit of transfer | Whole message (any size) | Packets (fixed upper size) |
| Storage at nodes | Large, disk | Small, RAM buffer |
| Delay | High, since entire message is received at each hop | Lower, pipelining of packets |
| Link occupancy | Link blocked for long messages | Short, fair sharing of links |
| Error handling | Whole message is resent | Only damaged packet is resent |
| Suitable for | Telegram, email, non-real-time | Internet, interactive and data traffic |
| Reordering | Not needed | Required at the destination |
| Header overhead | One header | Header in every packet |

For a message of M bits over k hops at rate R, message switching delay ≈ k·M/R, while packet switching with packet size p is about (M + (k−1)p)/R, which is much less.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is sent in message switching?
   A. Small packets
   B. Cells
   C. The whole message as one unit
   D. Bits
   Answer: C. The entire message goes node to node. (Key point: Unit)

2. Where is data stored at nodes?
   A. Message: RAM; packet: disk
   B. Message: disk (large); packet: RAM buffers (small)
   C. Both disk
   D. Neither
   Answer: B. Message switching needs large disk storage; packets need small RAM buffers. (Key point: Storage)

3. What is resent on error?
   A. Message: whole message; packet: only damaged packet
   B. Both whole
   C. Message: damaged part only
   D. Neither
   Answer: A. A packet scheme resends only the damaged packet. (Key point: Error handling)

4. Why is packet switching delay lower?
   A. Packets pipeline across hops
   B. Larger buffers
   C. Dedicated links
   D. No headers
   Answer: A. Packets pipeline so a hop need not receive the whole message. (Key point: Delay)

## Related in Data Communication

- [Circuit vs packet switching](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Acircuit-vs-packet-switching) — Data Communication, chapter 7, asked 4×
- [Switching, circuit vs packet, X.25 layers](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Aswitching-define-compare-x25-layers) — Data Communication, chapter 7
- [Packet switching](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Apacket-switching-explain) — Data Communication, chapter 7, asked 3×
- [Datagram vs virtual circuit switching](https://www.bctengineer.com/question.md?key=semester_5%2Fdata_communication%3Adatagram-vs-virtual-circuit) — Data Communication, chapter 7, asked 3×

## Related in other subjects

- [Circuit vs packet switching](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Acircuit-vs-packet-switching) — Computer Networks and Security, chapter 2, asked 3×
- [IPv6 migration; IPv4 vs IPv6 packet structure](https://www.bctengineer.com/question.md?key=semester_8%2Finternet_and_intranet%3Aipv6-migration-router-packet) — Internet and Intranet, chapter 2
- [Content filtering vs packet filtering](https://www.bctengineer.com/question.md?key=semester_8%2Finternet_and_intranet%3Acontent-filtering-packet-filtering) — Internet and Intranet, chapter 5
- [Circuit switch vs packet switch](https://www.bctengineer.com/question.md?key=semester_8%2Ftelecommunications%3Acircuit-vs-packet-switch) — Telecommunications, chapter 8