Get to grips with standardised technology

There are requirements ­ – and testing ­ – for interoperability, all of which will help to avoid the sort of issues we talked about earlier. There are four main types of DLNA device, just as with UPnP AV; Digital Media Servers and Digital Media Players do pretty much what you’d expect.

There are also Digital Media Renderers ­ – things like photo frames, wireless speakers or TVs ­ – and Digital Media Controllers, which can control what appears on a renderer; also in the mix are mobile versions, which tend to have slightly different requirements for the formats they should support. And, of course, some devices are more than just one type.

A media player TV or set-top box may also be capable of being used as a renderer, allowing you to select a photo on your mobile phone, for example, and send it directly to the TV, rather than having to browse the phone from the TV’s remote control.

If you’re thinking of buying, the DLNA website has a database of certified products to help you make sure you buy devices that will work together.

Other standards
The DLNA isn’t the only game in town, of course. There are some new standards emerging and some already here. Microsoft’s Windows Media Connect, for example, is also based on UPnP and so will work with a wide range of existing players, but offers better functionality when paired with another WMC device, such as the Xbox 360.

It may be tempting to look at if you have a new Windows Home Server system and a games console, but beyond the Xbox there aren’t many devices that support it fully.

If you use iTunes and its sharing functionality, you’ll find that music is shared using a protocol called DAAP (Digital Audio Access Protocol), and the way in which devices discover each other relies, instead of UPnP, on an Apple technology called Bonjour; Airport Express remote speakers use a different protocol too. Fortunately, that doesn’t necessarily mean you can’t pick and mix.

Many Nas units, for example, can run both a UPnP server, including DLNA-compliant ones, and at the same time share music via software such as Firefly, which implements the DAAP protocol needed for iTunes.

Similarly, devices such as the Soundbridge will see information that’s available via both DAAP and UPnP media servers, while a playback device that’s DLNA certified should see WMC servers too, since they’re both built on UPnP AV.

Linking up
It’s also important not to overlook the connectivity side of things; while the DLNA specs embrace Wifi and Bluetooth, those are both standards with different versions, and it’s important to make sure that you choose compatible equipment, especially with regard to things like encryption.

When it comes to higher quality media, though, many people are now ditching the crowded Wifi airwaves and using home powerline networking. With a rated throughput of 200Mbits/sec, even the real-world performance of Homeplug AV is good enough for high definition and, as far as your devices are concerned, they’re connected to a standard Ethernet network.