PROVIDING IPTV MULTICASTS

摘要

A method of operating a Reliable Transmission Protocol switch node to provide an IPTV multicast. IP packets transporting an encrypted media stream are received from an IPTV Head-end. The media stream contains complete image frames. Unencrypted identifiers identifying packets containing complete image frame data are also received. The received packets are stored in a buffer, and on receipt of a request from a media renderer to provide the IPTV multicast, the packet(s) containing the last complete image frame in the media stream and all subsequent packets are sent to the media renderer.