DLNA compliance testing: It ain't working
Iomega NAS not talking to Sony TV - whose fault is that?
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.
Iomega's Home Media Network Hard Drive apparently uses PacketVideo's  media serving software, as do other NAS (network-attached storage) devices, and the problem has apparently been encountered with other home NAS devices serving media files to playback products. PacketVideo states: "The PVConnect media server is DLNA-certified, and interoperable with hundreds of DLNA-certified home electronic and mobile devices."
PacketVideo produces the TwonkyMedia  code for manufacturers to include in their consumer electronics devices. TwonkyMedia firmware revisions have been shipped by Iomega to Morrison, so far to no avail. PacketVideo was unable to immediately comment on this.
For Morrison there was no problem with displaying JPEG images; it was an MP3 playback issue. Initially he endured a bout of finger-pointing between Iomega and Sony, but now Iomega is looking closely into the problem.
Iomega's EMEA product manager, George Mellissargos, said: "It is important for us that our devices play well with other DLNA devices and not only DLNA ones, since we also test against other UPnP devices that are not DLNA certified." (UPnP stands for Universal Plug 'n Play, which is a different device interconnection method.)
"The Home Media AV Streaming market is just starting to happen (at least for the simple consumers at home) and we definitely, all of us (vendors) have to be careful not to disappoint customers."
Morrison is getting good support from Iomega as it tries to diagnose and fix the problem, but one thing is clear - at present DLNA-certification is no guarantee DLNA-compliant devices will interoperate correctly.
The stakes here are high as DLNA promises to be the protocol enabling different suppliers' products - storage products, games consoles, smart phones, iPods, digital TVs etc - to play nice together and store, receive and play correctly the various standard digital media files.
DLNA-compliant devices should work together as simply and as surely as a 3-pin plug fits into an electricity socket or USB connector into USB socket. The compliance testing should screen out problems like the one Morrison has encountered before products hit the shops.
The DLNA organisation did not reply to emailed questions about this and Sony was also unable to respond. ®