On Sep 23, 2013, at 15:10, Simon Leinen <simon.lei...@switch.ch> wrote:
> Glen Kent writes: >> One of the earlier posts seems to suggest that if iOS updates were >> cached on the ISPs CDN server then the traffic would have been >> manageable since everybody would only contact the local sever to get >> the image. Is this assumption correct? > > Not necessarily. I think most of the iOS 7 update traffic WAS in fact > delivered from CDN servers (in particular Akamai). And many/most large > service providers already have Akamai servers in their networks. But > they may not have enough spare capacity for such a sudden demand - > either in terms of CDN (Akamai) servers or in terms of capacity between > their CDN servers and their customers. I have some anecdotal evidence that a large swatch of Telekom land in Germany was fed from two (2) Limelight servers in Frankfurt (?). Of course, packet loss to them during Wednesday evening was around 50 %. (I VPNed out of Telekom land to get my iOS 7 update, which was then no problem at all; that clearly shows that the access infrastructure wasn't overloaded.) It doesn't help that Apple's update software has no way to make use of the results of a prematurely aborted transfer; this is a recipe for bistable behavior. Grüße, Carsten
