Patent ID: 8375277

Claim:
A method of multicasting content information to a plurality of receivers via a data network, using data packets in a transport stream, wherein: the content information is encapsulated according to a container format that provides an optional field in a packet header portion; each respective one of the data packets forms a payload of a respective datagram in a connectionless communication protocol; the method comprises populating the optional field in each respective one of the data packets to carry a respective one of multiple sequential identifiers for identifying the respective data packet in a pre-determined sequence of the data packets; buffering at least part of the content information during the multicasting in a buffer; upon receipt of a request for a specific data packet containing a specific one of the identifiers from a particular one of the receivers, sending the specific one of the data packets via a unicast transmission to the particular receiver; maintaining a history of the specific data packets sent to each particular receiver via previous unicasts; based on the history, determining to send one or more further buffered data packets having further ones of the identifiers belonging to a particular range of the identifiers to one of the particular receivers; and sending the one or more further buffered data packets without receiving an associated request from the one of the particular receivers.