In an exemplary server implementation, a server is configured to retain at
least one independent frame for each video channel of multiple video
channels that are being distributed using multicast communications and is
adapted to respond to channel change requests from clients by
transmitting the retained at least one independent frame of a requested
video channel to a requesting client using a unicast communication. In an
exemplary method implementation, a method for fast channel changing in a
multicast video distribution architecture includes: detecting a channel
change request that indicates a requested channel, the requested channel
corresponding to a multicast group; and transmitting a retained intra
frame for the requested channel as a unicast communication.