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DLNA compliance testing: It ain't working

Iomega NAS not talking to Sony TV - whose fault is that?

SGI logo hardware close-up

Comment Alastair Morrison was stumped; his Iomega NAS sent MP3 files to be played on a Sony Bravia TV, and they stuttered to a halt after a few seconds, yet both devices were DLNA-compliant.

The Digital Living Network Alliance (DLNA) is an industry body concerned to develop standards to enable storage devices and playing devices to interoperate such that sound, image and video files can be stored on the former and sent to the latter for playback. The notion is the classic standards idea; have one open standard replacing a plethora of proprietary ones and provide a level digital media storage and playback playing field for consumers.

Device suppliers become members of the DLNA and their products get DLNA-compliance by passing tests at Independent Certification Vendors' laboratories (ICVs) that are accredited by DLNA to perform interoperability testing services as part of the requirements set by the DLNA certification and logo program. The certification program verifies that DLNA products comply with the DLNA Networked Device Interoperability Guidelines.

Scott Smyers, DLNA president and chairman, says: "The DLNA certification and logo program delivers a level of assurance to the industry and to consumers that products with a DLNA Certified logo have passed rigorous testing to be able to share digital content between devices within a home network."

But is DLNA-compliance worth the paper it's printed on? Alastair Morrison's Iomega Home Media Network Hard Drive and Sony Bravia KDL40W4500 digital TV are both represented as being DLNA-compliant. Iomega describes the HMNHD as enabling you to "play back your pictures, videos and music from digital media adapters such as game consoles, digital picture frames or networked TVs".

The Sony Bravia KDL40W5400 is described as having "DNLA media streaming capabilities, allowing you to view photos and listen to music from compatible networked devices".

Neither device is actually tested interoperating with the other. DLNA-compliant candidate devices pass formal tests on their own at the Certification Vendors' labs and, if they work, that is deemed to be that; they are assumed to then interoperate correctly with every other DLNA-compliant device.

There is no central DLNA consumer support facility. If consumers find devices don't work then they have to have recourse to the suppliers of each device concerned, a process almost designed to encourage finger-pointing between the suppliers.

Both Sony and EMC, Iomega's parent, are listed on the DLNA member list. There is a listing there for Sony's Bravia KDL40W5400.

But here's a curious thing. There is no listing of Iomega's HMNHD as a DLNA-compliant device on the DLNA website. In fact no Iomega device is so listed. However, there is a listing for a TwonkyMedia 4.4 (media serving code) product from PacketVideo.

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