membership reports and configures a plurality of sender threads based on these reports each sender thread transmits a multicast data stream with encoded multimedia content from a respective file to a corresponding multicast address in the open loop mode the sender transmits multicast data streams to all multicast addresses continuously application_number US 6157705 A description fig1 illustrates an example of a video delivery system that multicasts multimedia content from a head end 1 to a plurality of client devices 7 generically the head end equipment includes the respective video sources which can be a plurality of analog sources 2 and or a plurality of digital sources 2 u2032 the respective content is encoded compressed using e g mpeg encoders 3 in the case of analog sources and e g mpeg transcoders 4 in the case of digital sources the mpeg streams are transmitted to the subscriber terminals 7 also referred to as u2018 users u2019 or u2018 clients u2019 over a multicast network 5 network 5 must support ip multicast to enable a large number of users to view the same channel in this current configuration the head end 1 serves client terminals 7 distributed over large geographical areas over a large network 5 as known the client devices 7 could be pcs enabled with video player capabilities or tv sets with set top boxes stb today 39 s tv systems of the type shown in fig1 are designed to have every channel a tv provider offers flow to each set top box at the same time ready for the viewer to.