What is Multicast?

Multicast is a process that lets a server send a stream to multiple recipients simultaneously in a single transmission. In this one-to-many distribution architecture, a single IP router creates optimal one-to-many distribution paths to a multicast destination address. A multicast stream is published to a multicast address in a VLAN. A live encoder publishes one stream to the multicast address; then playback clients stream from the multicast address, not directly from the source. The VLAN replicates multicast streams for each playback client. Multicast is not supported over the public Internet.


Wowza Streaming Engine™ software can re-stream from a multicast address, allowing the stream to be played back in any supported client.


The Wowza Push Publishing AddOn includes a multicast publishing feature. In addition, Wowza® Media Systems provides a Silverlight player for playing multicast streams.  


When Streaming Engine software is used as a multicast source, it does not log play statistics of multicast playback clients. These statistics are not logged because they are not streamed directly from the Streaming Engine software; they are streamed from the multicast destination IP from which the stream is being published.

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