Caching system, apparatus, and method applied to network

A caching method applied to a network having a caching policy control device and at least one main cache device, the method comprising:

• receiving, by the caching policy control device, a content caching request sent by an external packet data network (PDN), and controlling, according to the content caching request, the at least one main cache device to cache external content, wherein the external content is content provided by the external PDN;
• and
• caching, by the at least one main cache device, the external content according to the control of the caching policy control device, wherein the at least one main cache device is connected to the caching policy control device, and is located on a data channel between an anchor gateway of the network and the external PDN.

A caching policy control device, wherein:

• the caching policy control device is connected to at least one main cache device on a network;
• and
• the caching policy control device is configured to receive a content caching request sent by an external PDN, and control, according to the content caching request, the at least one main cache device to cache external content, wherein the external content is content sent by the external packet data network (PDN).