What exactly is... IPTV?

Internet Protocol Television (IPTV), is based around the use of Internet Protocol (IP) as indicated by its name and this means that the service tends to be used in conjunction with telecommunications services of broadband Internet lines are the most widely used. There are two basic ways in which the materials for IPTV can be sent out as broadcast or 'multicast' material to many users simultaneously or it can be used to provide video-on-demand where the material is sent to just one subscriber who has requested that particular item. One important aspect of multicasting is the ability of the system to be able to select the required channel and change it as per the requirement. Channel selection is completed by using a special protocol known as IP Group Membership Protocol (IPGMP), this is a communications protocol used to manage the membership of Internet Protocol multicast groups, it is used by IP hosts and adjacent multicast routers to establish multicast group memberships.