When Apple releases a new iOS update, it is always delivered simultaneously to everyone around the globe. This could cause a massive traffic spike to internet provides. BT, a broadband network in the UK, just reported that the spike caused by iOS 5 was the company’s largest ever!

Here is what BT wrote to Cult of Mac.

Over the last two nights, BT has experienced the highest ever traffic levels over the UK broadband network.

Traffic levels were at their highest level ever seen within BT’s UK broadband network (wholesale through BT Retail and other content providers) on Wednesday night – this was sustained from the launch of Apple’s iPhone OS 5 until past midnight.

Last night (Thursday) saw the 2nd highest we’ve ever seen on the UK broadband network, less than 10Gbits/s lower than Wednesday and sustained for a longer period of time.

This exceeded previous peaks seen during Wimbledon and major England football matches. At a rough figure we were seeing over 80Gbits/s of extra traffic on the network last night (Wednesday). That would make it about twice the volume of the previous largest event, an England World Cup Football Game – which was during UK business hours, not the evening peak. Estimated traffic volumes from the Content Delivery Network (CDN) that Apple use were nearly double the peak last Tuesday.

Over 80Gbits/s is alot! Would be interesting to know what Apple’s update servers need to sustain when delivering a new update.