When we speak of the Internet data transfers and protocols, the normal process (that I'm aware of) is this:
- A request is sent to the server (some data uploaded)
- The server processes the request (on remote server)
- The response is sent back to the client (data downloaded)
However, how does a satellite TV's set-top-box go about updating its firmware? I am aware that it just fetches (or downloads data) directly from satellite, which is then deflated and installed on the system. But how does it manage to make the request for the download, since it can never transmit data up to the satellite as a "request".
This uni-directional data transfer baffles me, and I'd be glad if someone could explain the protocol please.