Unicast and multicast are two distinct forms of streaming media distribution. Each has unique strengths and weaknesses based on the nature of your audience and the type of content.
A unicast broadcast transmits a single stream to each player. Unicast streaming offers the benefits of interactivity between the player and server, easier setup, and multiple-bit-rate streaming capability. However, the number of users that are able to receive unicast streams is limited by the bitrate of the content and the speed of the server network. A large unicast audience can quickly overwhelm a network or server. Consider using unicast streaming if:
A multicast transmission creates a one-to-many relationship with clients. The server broadcasts a single stream, and users may then access the stream in progress. Users do not have control of content playback. Multicast streams are much less demanding on the server and network but may require network modification for multicasts and regular network traffic to coexist effectively. Consider using multicast streaming if: