Method for caching data and forwarding device

A forwarding device, wherein the forwarding device is located on a first content delivery path, the first content delivery path is a packet transmission path between first user equipment and a server, a quantity of all forwarding devices on the first content delivery path is k, the forwarding device is an ith forwarding device, i is an integer that is greater than or equal to 1 and that is less than or equal to k, and the forwarding device comprises:

• a memory, configured to store a local caching gain corresponding to an identity of first content;
• a receiving circuit, configured to receive a first data packet from the server, wherein the first data packet comprises a caching gain, the first content, and the identity of the first content, the caching gain in the first data packet is a maximum value of local caching gains of all the forwarding devices on the first content delivery path, the local caching gain corresponding to the identity of the first content is generated by calculation according to a first parameter and a popularity of the first content, the first parameter is used for identifying bandwidth consumed by transmitting the first content between the ith forwarding device and the server, and the local caching gains of all the forwarding devices on the first content delivery path correspond to the identity of the first content;
• and
• a processor, configured to determine whether the caching gain in the first data packet matches the local caching gain that corresponds to the identity of the first content and that is stored in the memory;
• wherein the memory is further configured to:
• when the processor determines that the caching gain in the first data packet matches the local caching gain that corresponds to the identity of the first content and that is stored in the memory, cache the first content that is in the first data packet.

A controller, wherein the controller communicates with first user equipment, a server, and each forwarding device on a first content delivery path, the first content delivery path is a packet transmission path between the first user equipment and the server, and the controller comprises:

• a processor, configured to calculate a local caching gain of first content for each forwarding device on the first content delivery path, wherein an ith forwarding device is any one of forwarding devices on the first content delivery path, a local caching gain of the first content of the ith forwarding device is generated by calculation according to a first parameter and a popularity of the first content, and the first parameter is used for identifying bandwidth consumed by transmitting the first content between the ith forwarding device and the server;
• and obtain a first caching gain, wherein the first caching gain is a maximum value of local caching gains of all forwarding devices on the first content delivery path, and the local caching gains of all the forwarding devices on the first content delivery path correspond to an identity of the first content;
• and
• a sending circuit, configured to send the first caching gain to the server periodically and send the local caching gain of the first content to the ith forwarding device periodically.