Orhan Ergun No Comments

Efficient data transfer, optimised resource usage , simplified configuration, optimum bandwidth usage are the main characteristics of Multicast.

In the diagram below; unicast and multicast flows are shown.

From the source, if same packet will be sent , with unicast transport you send two copies.

This is inefficient for the source PC , for the routers , for the links.

Instead, if multicast transport is used, only one copy is sent by the sender.

Receivers join to the multicast group, PIM protocol tells to the source that somebody is interesting with your packet.


I recorded a podcast on packet pushers podcast.

I shared the link below in this post.

My guest is very distinguished speaker, author Beau Williamson.

He wrote one of the first book on the subject ‘ Developing IP Multicast Networks ‘.

Some of the topics in the podcast :

  • What are the drivers for the Enterprise Networks and  What are the general use cases in real life ?
  • Layer 2 and Layer 3 Multicast Concepts.
  • PIM Dense , Sparse and Sparse-dense modes.
  • PIM Any Source Multicast (ASM) , PIM Source Specific Multicast(SSM)  and PIM Bidirectional (Bidir)

You will surprise to hear that how design choice (Specifically ASM)  effected John Chamber’s internal speech.


Orhan Ergun

Beau Williamson

You can listen the podcast by clicking here.

What about you ?

Do you have multicast in your network ?

Let’s talk about it  in the comments box below.

0.00 avg. rating (0% score) - 0 votes