How Slingbox Works

Slingbox Technology

Slingbox motherboard
Slingbox motherboard
Photo courtesy Tom's Hardware

You can set up a Slingbox for every video component in your home, but you can only access one Slingbox at a time. Depending on your Slingbox model, you can connect up to four components to one Slingbox. If you hook up your digital cable box and your DVD player to a single Slingbox, you can switch between them at the click of a button on your virtual remote control. You should check for the latest firmware updates before using your Slingbox.

The Slingbox is actually a pretty straightforward machine. The main components involved in slinging your video signal are:

  • A digital media processor that handles digital signal processing and video encoding
  • An Ethernet port (RJ-45)
  • A TV tuner

The basic process looks like this:

  1. You connect your TV's video output to the Slingbox tuner.
  2. The Slingbox grabs the video signal from your TV.
  3. The digital media processor (acting as a DSP) converts the signal into digital data the Slingbox can manipulate.
  4. The digital media processor (acting as a video encoder) compresses the data using a Windows- or Mac-compatible codec.
  5. The Slingbox broadcasts the compressed data stream in real time via the Ethernet port. It uses a proprietary streaming protocol called SlingStream, which adjusts the stream on the fly to adapt to varying network speeds.
  6. You access the stream via your home network or a broadband connection using SlingPlayer software on your computer.

To access the stream from your Slingbox via the Internet (as opposed to your home network), you tell the Sling Media server to find it for you. Every Slingbox has a Finder ID that's stored on your computer. When you initiate a remote connection to your Slingbox, your computer tells Sling Media's server what the Finder ID is, and the server matches your box's ID to its IP address. When you change the channel using your virtual remote, the command travels to your Slingbox just like any other Internet command -- as upstream data intended for a particular IP address. Because the video stream is downstream data, and remote commands are upstream data, the video travels faster than the commands. You may experience a delayed response when you click a button on your virtual remote.