Content delivery

A method for delivering content at varying qualities from a server to multiple clients across a network, the content being arranged in representations of differing qualities, each representation comprising segments addressable by client requests, comprising:

• at a server side converter:
• issuing unicast requests to the server for segments of multiple representations of the content;
• converting each of the multiple representations of the content to respective multicast datagram streams, each representation being assigned to a corresponding multicast IP address;
• and
• deliver the multicast datagram streams onto the network;
• at a client side converter:
• receiving requests for content from the clients;
• determining a representation of the content to obtain;
• subscribing to the multicast datagram stream that comprises the determined representation of the content;
• converting the multicast datagram stream back to segments available to the client by unicast request;
• intercepting client requests for content;
• intercepting response messages from a server;
• and
• modifying the response messages to be sent to the client by altering an address in the response message so that client requests for content are redirected to the client side converter.

A method for delivering content at varying qualities from a server to multiple clients across a network, the content being arranged in representations of differing qualities, each representation comprising segments addressable by client requests, comprising:

• receiving requests for content from the clients;
• determining a representation of the content to obtain;
• subscribing to the multicast datagram stream that comprises the determined representation of the content;
• converting the multicast datagram stream to segments available to the client by unicast request;
• intercepting client requests for content;
• intercepting response messages from a server;
• and
• modifying the response messages to be sent to the client by altering an address in the response message so that client requests for content are redirected to the client side converter.