iPlayer has been a shining example of the Video-on-Demand (VOD) capability of Virgin's network - Virgin was the first TV platform to provide iPlayer and as of January 2011, 16% of all iPlayer views were made from Virgin TV customers.
With Virgin, there's dedicated frequencies within the physical cable for each service that enters your home. Think of the cable as a 5 line Motorway, with separate traffic lanes for Linear TV Channels, VOD, Home Broadband, TiVo's 10Mb Broadband and Voice Data for your phone.
Until now, when you've requested some iPlayer content on TiVo, its been delivered as a MPEG 2 stream via the 'VOD' lane of the Motorway/Cable, and that iPlayer content, along with the majority of other VOD content, has been delivered from your local headend. There's over 50 regional headends and they each contain VOD servers which provide the on-demand content for your area.
One problem with that approach is keeping content in sync for the VOD servers at those regional headends. When new content becomes available (from the BBC and every other supplier of VOD content), it needs to be copied to all of those regional headends. That's why you may not have VOD content which other customers report as being available in their area, the recent rollout of Sky Anytime content is a recent example of this.
With 15.2 on TiVo (and only on TiVo - V and V+ HD boxes are unaffected), that's changed for iPlayer. Now, all iPlayer content is delivered directly from the BBC. The advantages of this approach is that as soon as the BBC make the content available, its also available for your TiVo, and the delay between a BBC programme being broadcasted and becoming available to watch on TiVo via iPlayer, is greatly reduced.
It also means a lot more iPlayer content is available to watch via TiVo, compared to the older V/V+ HD boxes - up to 950 hours on TiVo from 350 hours on older Virgin boxes.
It sounds good, and it also has the advantage of not using one of TiVo's three tuners to watch iPlayer content. So you could watch last week's Top Gear while recording up to three programmes.
So....why all the recent complaints about iPlayer not working since the 15.2 update?
Well, leaving aside the annoying delay between requesting iPlayer content and the completion of the iPlayer app loading (seriously Virgin, can't we just play the damn content already instead of loading the app first?!?), the problem isn't TiVo's dedicated broadband connection which provides up to 10Mb of bandwidth - that's more then enough bandwidth to stream HD iPlayer content which requires a bitrate of 3.5Mb.
The problem is somewhere else in the network - either a lack of bandwidth between the Beeb and your TiVo, or a lack of server capacity at the BBC's server farms or content delivery network, in which case the iPlayer servers are being bombarded by so many requests from VOD-hungry TiVo's that they're struggling to stream content without buffering issues.
Virgin have acknowledged there's an issue and are working to fix it. Someone, somewhere, has been caught out by the extra bandwidth and/or server capacity requirements needed to feed iPlayer content to all those TiVos - and there isn't exactly a lack of demand for them, especially at this time of year.
Looking ahead, Virgin will potentially face the same issues as they go from using the legacy delivery system of VOD (streaming MPEG 2), to using TiVo's broadband connection (streaming MPEG 4) to provide content from other on-demand providers like 4oD, Demand Five and Warner. Hopefully Virgin can avoid the issues which has made the unmissable missed for fans of BBC iPlayer.