Finishing up

Finishing up our chain of events to play music from a NAS based on UPnP (Universal Plug and Play) protocols, we discovered the controller displays the library contents sitting in the NAS, which is a network connected hard drive. Let's imagine we picked the track Layla, by Eric Clapton. That track is actually nothing more than a group of recorded bits on a hard drive. What distinguishes those bits from other groups of bits is an address; a memory location. When you touch play on the controller, the track's address information (where it lives) is sent to the player and told to connect. Once connected the bits are streamed over the network to the player, converted (in the player) to an acceptable format and reach the DAC for rendering. During this process the controller is no longer involved - you can turn it off or do whatever you wish - the only two elements involved are the NAS and the player. So, what have we learned from a brief understanding of a NAS? Well, tomorrow we'll cover the upside and downside of connecting with a NAS, but to close for today, let's review:

• A NAS is a hard drive with a computer attached to it
• NAS only connects over the home's network
• NAS do not have players built in
• NAS can connect to desktop computers, or embedded computers, but they require a controller and player to play music stored on them
• NAS nearly always use a type of protocol known as UPnP to discover and connect to them