When a user applies to join a multicast group, controllable multicast checks whether the application is valid to filter invalid and unauthorized join requests.
In conventional multicast services, there is no restriction on multicast users. Currently-used multicast protocols such as IGMP, PIM, MSDP, and MBGP are not designed with a user authentication mechanism. Users can join a multicast group by sending IGMP Report messages, and then receive multicast packets from the multicast group.
With the large-scaled deployment of IPTV services, telecommunication operators have to distinguish users. Only users that pay the fee have the rights to join multicast groups and receive multicast programs.
Because conventional multicast services cannot meet the requirements of IPTV services, multicast control is introduced to control the rights of users to join a certain multicast group. When a user applies for joining a multicast group, the device checks whether the request is valid. In this manner, the device can reject invalid and unauthorized requests.