1. Video and television multicasting, unicasting and broadcasting over internet services

2. The method includes: monitoring the public channel of a multicasting server, wherein the public channel is used for multicasting the information of subfiles needed for upgrading device; acquiring the information of subfiles needed for upgrading device from the message of the public channel, wherein the information includes the address of sub channel for multicasting the subfiles; switching to the sub channel according to the address of the sub channel; receiving the subfiles from the sub channel of the multicasting server and enabling the subfiles to take effect.