Project IPTV Platform

VII. IPTV Multicast
1. Introduction
The most important application of the multicast is IPTV. With the coming of the Triple
play including voice, data and video, all in the same network, management of the
network resources has become necessary. Therefore multicast is an important part of
the IPTV broadcasting.
The main purpose of the multicast is to send data to many people only once, rather than
sending a separate copy of the data to each user, routers along the way to the
destinations make copies as needed, and multicast receivers just have to request data to
receive it.
The destination IP address in a multicast is address of the multicast group,
Typically in IPTV, the TV channels are multicast in the core network and only forwarded
in the access network when clients request the respective TV channels. Compared to the
core network, the access network has only limited bandwidth capacity involving a good
management of traffic in this area.
Figure 1: IPTV network distribution
In figure 1, an example of IPTV distribution network for broadcast TV is given. The TV
channels are multicast from the streaming server to the Set Top Boxes (STB), the user
equipment which decodes he video stream and displays it on a TV. During transport the
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