Content delivery

A network element for managing content delivery to a client device, said content comprising a sequence of segments, said network element adapted in operation to:

• receive requests for segments from a client device, and transmit the requested segments to the client device by unicast, wherein the network element is further adapted in operation to obtain the transmitted segments by:
• i) requesting one or more of the requested segments from a unicast content source until a decision is made to join a multicast channel;
• ii) requesting further segments from a unicast content source before the corresponding requests for the further segments are received from the client device, and storing the further segments until requested by the client device;
• and
• iii) joining a multicast channel and receiving segments over multicast, and storing the segments until requested by the client device;
• wherein the network element is further adapted in operation to delay a multicast join command from being issued until the network element has obtained content by unicast faster than that content is being requested by the client device, so that the obtained content has caught up with the content available on the multicast channel.