1. Overview
- These terms define how data is transmitted over a network:
- Unicast: One-to-one
- Multicast: One-to-many (specific group)
- Broadcast: One-to-all
2. Definitions with Examples
A. Unicast
- Definition: One sender → One receiver.
- Analogy: A private phone call.
- Use Cases: Sending an email to one person, downloading a file.
- Networking Example: Accessing a specific website.
B. Multicast
- Definition: One sender → Multiple specific receivers (group communication).
- Analogy: A conference call with invited participants.
- Use Cases: Webinars, live video streaming to selected users.
- Networking Example: IPTV (Internet Protocol Television).
C. Broadcast
- Definition: One sender → All devices in the network.
- Analogy: A public announcement over a loudspeaker.
- Use Cases: Network discovery, sending alerts to all systems.
- Networking Example: ARP (Address Resolution Protocol) requests.
3. Key Differences
| Feature | Unicast | Multicast | Broadcast |
|---|---|---|---|
| Destination | Single receiver | Group of specific receivers | All devices in the network |
| Bandwidth Usage | High (one-to-one) | Efficient (one-to-many) | High (one-to-all) |
| Efficiency | Low for many users | High for group communication | Low for large networks |
| Use Cases | Web browsing, file transfer | Streaming, video conferencing | Network discovery, ARP |
| Scope | Local or across networks | Group-based | Limited to local networks |
4. IP Address Ranges
- Unicast: Regular IP addresses → e.g.,
192.168.1.10. - Multicast: Class D IPs →
224.0.0.0to239.255.255.255. - Broadcast: Special IP →
255.255.255.255.
5. Quick Recap
- Unicast: One-to-One → Example: Downloading a file.
- Multicast: One-to-Many → Example: Live video streaming.
- Broadcast: One-to-All → Example: ARP request.
MCQ
1. Which of the following describes Unicast communication?
- A) One-to-one communication
- B) One-to-many communication
- C) One-to-all communication
- D) Many-to-one communication
- Answer: A) One-to-one communication
2. In which scenario is Multicast communication typically used?
- A) Sending emails to a single recipient
- B) Streaming live events to a group of subscribers
- C) Sending a request to all devices in a network
- D) File transfer from one system to another
- Answer: B) Streaming live events to a group of subscribers
3. What type of address is used for Broadcast communication in IPv4 networks?
- A) Loopback address
- B) Broadcast address (e.g., 255.255.255.255)
- C) Multicast address
- D) Anycast address
- Answer: B) Broadcast address (e.g., 255.255.255.255)
4. How does Multicast differ from Broadcast communication?
- A) Multicast sends data to specific devices, while Broadcast sends data to all devices.
- B) Multicast requires IPv6, while Broadcast is used only in IPv4.
- C) Multicast is one-to-one, and Broadcast is many-to-many.
- D) Broadcast is more bandwidth-efficient than Multicast.
- Answer: A) Multicast sends data to specific devices, while Broadcast sends data to all devices.
5. Which of the following IP ranges is reserved for Multicast communication?
- A) 0.0.0.0 – 127.255.255.255
- B) 224.0.0.0 – 239.255.255.255
- C) 240.0.0.0 – 255.255.255.255
- D) 192.0.2.0 – 192.0.2.255
- Answer: B) 224.0.0.0 – 239.255.255.255
6. What is a drawback of Broadcast communication in a network?
- A) It requires multicast routing protocols.
- B) It uses excessive bandwidth by targeting all devices in the domain.
- C) It cannot operate in IPv4 networks.
- D) It requires a separate channel for each transmission.
- Answer: B) It uses excessive bandwidth by targeting all devices in the domain.
7. In IPv6, which communication type is used instead of Broadcast?
- A) Multicast
- B) Unicast
- C) Anycast
- D) Peer-to-peer
- Answer: A) Multicast
8. What is a key use case for Anycast communication?
- A) Efficient distribution of live video streams
- B) Redirecting users to the nearest DNS server
- C) Sending ARP requests across a network
- D) Broadcasting software updates
- Answer: B) Redirecting users to the nearest DNS server