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Differences Between Broadcast and Multicast

In network communications, broadcast and multicast are two distinct data transmission methods. Broadcasting can be likened to a radio broadcast, indiscriminately sending data to all devices connected to the network. On the other hand, multicast functions similarly to a subscription service, where only subscribed or member devices receive specific data streams. These transmission strategies are fundamental for effective network traffic management and targeted data delivery. This article aims to clarify the differences between broadcast and multicast, elucidate their significance, and discuss their roles in streamlining network operations. Let's delve deeper into these concepts.

What is broadcast?

Broadcast streaming distributes live or on-demand video and audio content over the Internet to large audiences. Broadcasters deliver programs in real-time to viewers without requiring them to download files before playing them.
With broadcast streaming, radio, television, or digital content is continuously transmitted as data flows through the internet to the audience's computers or devices. Streaming technologies allow this transmission to occur as the user downloads the file rather than waiting for the entire file to finish downloading before viewing or listening can start. This enables nearly instant access to live broadcasts or on-demand content.
Broadcast streams are usually delivered through content delivery networks, allowing efficient distribution to many viewers globally. Streaming providers enable broadcasters to reach wider audiences by making their programs accessible online, beyond traditional broadcasting. Key types of streaming for broadcasters include live streaming, online linear channels, catch-up services, and video-on-demand. The accessibility of streamed content has led to increased internet viewing by audiences across devices.

What is multicast?

Multicast streaming is a clever method for sending live or on-demand content to a large audience at the same time. It uses a ‘one-to-many’ approach, significantly reducing the amount of duplicated data travelling across the network. Think of it like this: with regular streaming, every single viewer gets their own copy of the video. That can create a lot of extra traffic! Multicast is more competent; it uses special routers and switches to send a single stream that branches out only when it reaches devices they want to watch.

This streamlined approach maximizes your internet connection by ensuring data isn't sent where it's not needed. This means many people can watch the same broadcast without causing bottlenecks in the network.

Big streaming platforms love multicast streaming because it helps them manage costs while ensuring their service works smoothly for huge audiences. With multicast, they can reach people worldwide on various devices without slowing down. Overall, multicast makes large-scale streaming possible, leading to a faster, more reliable, and less expensive viewing experience for everyone!

Key differences between broadcast and multicast

While broadcasting and multicasting may sound similar, these technologies differ in several ways. The table below compares broadcast and multicast:

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Let's dive into the details of each feature to grasp the differences between broadcast and multicast better:

1. Audience reach

  • Broadcast streams are openly available for anyone to access, similar to traditional radio and TV broadcasts. There is no limit on how many clients can receive the stream.
  • Multicast streams are sent only to specific devices or users who are members of a designated multicast group. You cannot access a multicast stream unless you have been granted access.

2. Network bandwidth utilisation

  • With broadcast streams, each additional client accessing the stream consumes additional bandwidth. The total bandwidth needed scales directly with the audience size.
  • Multicast streams use a constant amount of total bandwidth, no matter how many viewers there are. The stream is replicated as needed by network hardware.

3. Reliability with larger audiences

  • As more clients access a broadcast stream, reliability often suffers from network congestion and lag. Picture quality or buffering may be impacted.
  • Multicast streams stay reliable despite reaching massive audiences numbering in the millions. Efficient protocols and distribution techniques prevent congestion.

4. Streaming costs

  • Similar to bandwidth use, costs for broadcasting scale up as more people watch the stream. Increased traffic means higher provider fees.
  • Multicast traffic costs remain steady no matter how many people access the stream in the multicast group.

5. Infrastructure and configuration

  • Broadcasting can work over basic networks with no special configuration.
  • Multicast requires changes to network routers and switches to enable optimised distribution. Certain hardware or software support is needed to handle multicasting.

Overall, broadcasting reaches anyone easily but faces challenges scaling up. Multicasting provides consistent service to specific groups but needs a supporting infrastructure.

When to choose broadcast vs. multicast

Choosing between broadcast and multicast streaming depends on your goals and setup. Here are some factors to consider when deciding between broadcast and multicast streaming:

  1. Audience size: Broadcast streaming may be the better option if you have a large audience. It allows you to reach a wide audience simultaneously without needing individual connections.
  2. Network capacity: Multicast streaming is more efficient regarding network usage, sending a single stream to multiple recipients. This can be beneficial if you have limited network capacity.
  3. Quality of service: Broadcast streaming can offer advantages in minimising interruptions like buffering for individual viewers, especially on less reliable connections. Multicast in well-managed networks can achieve excellent quality of service, but it requires careful setup.
  4. Security: Multicast streaming can be more secure, as it only sends the stream to authorised recipients. This can be important if you're streaming sensitive content. Ultimately, choosing between broadcast and multicast streaming depends on your specific needs. Consider the factors above and any other relevant factors to make an informed decision.

Efficient video conferencing: How Digital Samba leverages simulcast for optimised streaming

Video conferencing can strain your network, especially with large groups. Digital Samba uses simulcast to solve this problem, ensuring video calls stay smooth and clear.

Here's how it works: Digital Samba's SDK/API determines what each person's device can handle. Instead of sending everyone the same high-quality video stream, it sends multiple versions simultaneously. This might include a high-resolution stream for powerful computers and a low-resolution one for phones on weaker connections.

This clever approach means no one suffers from lag or choppy video. Everyone gets the best possible stream for their setup. Moreover, it prevents your network from being clogged with unnecessary data.

Digital Samba's SDK/API uses a simulcast to relieve network pressure. This guarantees fantastic video conferencing experiences regardless of the number of people on the call or what devices they're using.


Broadcast and multicast both transmit data, but differently. Broadcasting is like a megaphone, sending the same message to everyone. Multicast targets a specific group, like a private meeting. Multicast is ideal for live video streaming to large audiences, as it conserves network resources. Broadcast is simpler to set up but can struggle with huge numbers.

The best choice depends on your audience size, network capacity, and security needs. Digital Samba's SDK/API with Simulcast shines for effortless video conferencing. It cleverly adjusts video quality for each participant's device, ensuring a smooth experience while minimising network strain.

Ready to upgrade your video communication? Sign up for Digital Samba and enjoy 10,000 free minutes!

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