Methods and apparatuses for transferring data

A request including an identifier is transmitted for streaming media data to be delivered to caching proxy server and for data associated with streaming media data. The streaming media data is received and stored on a memory which is controlled by caching proxy server and the data associated with streaming media data is received. Independent claims are also included for the following: (a) Data transmission method; (b) Caching proxy server operating method; (c) Method of negotiating for various types of streaming media data by caching proxy server; (d) RTP header extending method; (e) Method of frame thinning by caching proxy server; (f) Method of frame thinning by client; (g) RTP packet transmissions transmit time using method; (h) Machine readable medium containing data transmission program; (i) Machine readable medium containing RTP header extending operation program; (j) Machine readable medium containing streaming media data negotiating operation program; (k) Machine readable medium containing frame thinning operation program by caching proxy server; (l) Machine readable medium containing frame thinning operation program by client; (m) RTP packet transmission operation program readable medium; (n) Caching proxy server; (o) Server data processing system; (p) RTP header; (q) Frame thinning caching proxy server; (r) Client.