It is provided are a server including: a storage module for storing original files and characteristics of the original files; an encoding module for encoding the original files stored in the storage module to generate encoded symbols; an information acquisition module for communicating with at least one transmission node and acquiring state information from the at least one transmission node; a control module for calculating a number of the encoded symbols to be sent to the at least one transmission node for caching based on the characteristics of the original files stored in the storage module and the state information of the at least one transmission node acquired by the information acquisition module; and a communication module for sending the encoded symbols to the at least one transmission node based on the number of the encoded symbols calculated by the control module.