Bittorrent udp-tracker protocol extension: "A tracker with the protocol 'udp://' in its URI is supposed to be contacted using this protocol.
This protocol is supported by xbt-tracker.
For additional information and descritptions of the terminology used in this document, see the protocol specification
All values are sent in network byte order (big endian). The sizes are specified with ANSI-C standard types.
If no response to a request is received within 15 seconds, resend the request. If no reply has been received after 60 seconds, stop retrying."