On an IP Network, IP Multicast uses data packets and sends them to a subset of nodes, called a multicast group. The basic concept is that source host only sends one copy of data to the destination host over a network. This destination is actually the address of a multicast group which comprises of many receivers, all of whom receive the same copy of the data, which allows only the destination hosts in the multicast group to receive the data while the others in the network are unable to receive it.

Multicast is a very specific implementation and for it to stream successfully, it is essential that all nodes and devices (switches, routers etc.) in the network, from the server to client, should all be Multicast enabled. 

Note: It is important to note that Multicast scenario in VIDIZMO only works on IE Explorer which uses the Windows Media Player.
Other players or browsers are not supported for Multicast streaming from VIDIZMO. 

A multicast requires that several files be present in order for the player to successfully view the stream. This wizard helps you create or modify those files, which include: 

  • A multicast information file (.nsc): This File enables Windows Media Player to decode the stream.
  • An announcement file (.asx). This file directs Windows Media Player to the location where your content is stored.

By default, these files are is stored in the following location:


Click here to learn more on How To Configure Live Streaming Using Multicast.


Here is how you can set up a Multicast environment in Windows Media Server:

1. Prerequisite to setting up a Multicast environment in Windows Media Server is the availability of a Publishing Point

To create a Publishing Point, please refer to the  Section 1, Configuring ECDN in VIDIZMO > Step 3 of How To Setup A Publishing Point.  

2. If you are running the Multicast Announcement Wizard for the first time, proceed as described in Section 2, Configuring A Streaming Server In Windows > Step 12, How To Configure Live Streaming Using Multicast

This wizard will generate the .nsc and .asx files required to make this Windows Media Server multicast enabled. 

3. On the other hand, if a Publishing Point is already available, the wizard needs to be run again.

Here are some probable scenarios where the Multicast Announcement Wizard will need to be run again:

- Using a Publishing Point created earlier: In order to use the same publishing point created earlier in the Windows Media Server, for a stream using a different encoder, you will have to overwrite the .nsc file by running the Multicast Announcement Wizard again. 

- Unable to stream: If for some reason you are unable to stream, e.g. the network does not have the capability to stream a high definition stream. You will then have to change the encoding to a lower resolution in your encoder and run the Multicast Announcement Wizard again to overwrite the .nsc file.

In these cases you should proceed as follows:

1. Access the Windows Media Server and select your publishing point. On the right-hand side, you will get a number of tabs. From them, select the Announce tab, and then click "Run Multicast Announcement Wizard".

2. On the popup window, click on the "Next" button. 

The rest of the steps in the Multicast Announcement Wizard are the same as described in Section 2, Configuring A Streaming Server In Windows > Step 12, How To Configure Live Streaming Using Multicast. 


Subject: Publishing Point

Action: Get, Update, Delete, Add