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 a first user device and a server, a quantity of all forwarding devices on the first content delivery path is k, the forwarding device is a first 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 a server, wherein the first content delivery path is a packet transmission path between a first user device and the server, the first data packet comprises a caching gain, first content, and an identity of the first content, the caching gain is a maximum value of local caching gains of all the forwarding devices on the first content delivery path;
• and
• a processor, configured to determine whether the caching gain in the first data packet matches a local caching gain corresponding to the identity of the first content, wherein the local caching gain 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 first forwarding device and the server;
• wherein the memory is further configured to:
• when the processor determines that the caching gain matches the local caching gain that is stored in the memory, cache the first content that is in the first data packet.

A controller, wherein the controller is configured to communicates with a first user device, a server, and each forwarding device of one or more forwarding devices on a first content delivery path, the first content delivery path is a packet transmission path between the first user device and the server, and the controller comprises:

• a processor, configured to calculate a local caching gain of first content for each forwarding device of the one or more forwarding devices on the first content delivery path, wherein a first forwarding device is a forwarding devices on the first content delivery path, a local caching gain of the first content of the first 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 first 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 of the one or more forwarding devices on the first content delivery path, and the local caching gains of all the forwarding devices of one or more 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 first forwarding device periodically.