Difference Between Unicast, Broadcast, and Multicast in Computer Network

The term cast used here refers to the stream of packets (data) transmitted from a client/ clients to a recipient/ recipients over a communication channel for establishing communication. We will discuss the difference between unicast, broadcast, and multicast in computer networks in this article. All three of these are types of IP routing. So let us first look into their individual functionalities.

What is Unicast in Computer Network?

Unicast information transfer is very helpful when a single sender transmits data to a single recipient. In simple words, it is called a one-to-one type of transmission. For instance, we can consider a device with an IP address of 10.1.2.0 that is willing to send data packets (traffic stream) to a device with an IP address 20.12.42 (while both of these belong to different networks). In this case, the device will use a unicast data transfer. This mode of data transfer is the most common one among various networks.

What is Broadcast in Computer Network?

Broadcast data transfer occurs when one sender transmits data to multiple recipients at any given time. There are basically two major types of broadcasting transfer techniques:

Limited Broadcasting – It is helpful when a sender in a network wants to transmit data to the devices over the same network in which it resides. A device will append a limited broadcasting address in the datagram’s destination address to achieve limited broadcasting. It is reserved for transferring data from a single client to all the recipients over the same network.
Direct Broadcasting – It is helpful when a sender in a network wants to transmit data to the devices residing in an altogether different network. A device translates all the part bits of the Host ID of a destination address to 1. It is known as Direct Broadcast Address for transferring information in the datagram header.

Broadcasting is mainly helpful for audio and video distribution by television networks. ARP (Address Resolution Protocol) is one of the most important protocols in this class that resolves the IP address to a physical address. It is an important step for underlying communication.

What is Multicast in Computer Network?

Multiple senders and recipients participate in the process of data transfer in Multicasting. In the multicast method, the traffic reclines between the boundaries of broadcast (from one to all) to unicast (from one to one). The multicast process lets the servers direct a single copy of data streams to get simulated and routed to the hosts that requested them in the first place. The IP multicast requires support from various other protocols such as Internet Group Management Protocol (IGMP) and Multicast routing for the working. Also, Class D stays reserved for multicast groups in the case of Classful IP addressing.