The difficulty of predicting and coping with bandwidth demands is highlighted by the release of iOS 5 which created unprecedented levels of traffic demand, with BT Operate reporting that within BT's UK broadband network that peak usage exceeded previous massive events. The spike was in fact twice the size of the previous largest event, an England World Cup match that took place during business hours.
The BT network saw a spike that started at the launch of the new iOS operating system, and carried on through to midnight. The Thursday evening saw a more sustained spike, but was 10 Gbps (Giga bits per second) less than the Wednesday. To give some idea of the overall scale the Wednesday saw around 80 Gbps of extra traffic compared to a normal night.
BT Operate who look after BT Retail, Wholesale through BT Retail and other content providers networks stated that "despite the above increase in volumes within our core network we saw negligible issues with network congestion". The story across other providers appears to have been a week of an increase of complaints about rising latency and slower traffic, so before people jump ship from providers due to poor network performance it would be wise to wait a few more days and see if the performance returns to more normal levels.
The National Grid attempts to anticipate the level of demand at peak times, and broadband providers are in a similar position, but it seems past models of behaviour keep being broken. Cloud based computing and automatic updates to popular operating systems, if quietly slipped out the door, risk causing chaos, particularly if a situation arises where two competing devices release large updates at the same time.
Perhaps one good thing is that the UK broadband network did not go into meltdown, and showed a reasonable ability to cope with big spikes in demand which may become more common in 2012 with the Olympics. The load on fixed line broadband during 2012 is likely to be video from live events, where as for mobile services, it will be the constant updates to social networking sites, and the growing use of Eye-Fi devices to upload photos from digital cameras as they are taken to online photo sites.