"iOS is one of the large-scale events," agreed James DeMent, service line director at Akamai, in an interview. "Windows 10, with the number of devices [eligible] and the amount of demand, has that same type of buzz."
The massive surge in download traffic -- Microsoft's reserved 13 times what Apple maxed out at with iOS 8 -- will jam up many ISPs' (Internet service providers) capacity at "interconnection points," the junctions where the ISP's network connects to the Internet backbone or to other carriers. "ISPs already know that their interconnection points in some cities are going to be overloaded," said Rayburn.
To maintain an acceptable quality of service (QoS) for their customers, not all of whom will be seeking Windows 10 but streaming audio or video or simply browsing the Web, ISPs will "rate limit" the speed of the Windows 10 downloads, Rayburn added. In other words, although someone may have a 40Gbps (gigabit per second) connection to the Internet through their ISP, the 3GB Windows 10 download will not be reaching them at that rate.
Microsoft has been unable to get more capacity, Rayburn said, because the Windows 10 roll-out, with interest fueled by the free upgrade deal, is a one-time event: CDNs were hesitant to allocate more to Microsoft because doing so would have impacted their ongoing customers. "That's part of the reason why it has not been capable of handling this," said Rayburn.
Although the anticipated slowdown of downloads may not be visible to most customers -- for the simple fact that Microsoft is delivering the upgrade in the background -- the congestion will stretch out the time it takes Microsoft to get the upgrade to X number of users.
That hints at a longer release schedule than many may expect or hope for.
The huge scale of the event could also affect the Internet in general. "I've never used the term 'break the Internet' because most of the time people say that, they are simply overhyping an event on the Web," said Rayburn. "But with the volume of downloads that Microsoft is expecting and the capacity they have already reserved to deliver the software, the Internet is in for some real performance problems this week."
Akamai, the CDN Rayburn believed would have the largest share of Microsoft's Windows 10 business, declined to speak about specific companies, much less customers. But DeMent was willing to talk in general terms.
"If something isn't delivered or configured properly, it could take down the intercontinental Internet," said DeMent.
When asked about staggered delivery and pre-loading -- approaches Microsoft will employ to disseminate Windows 10 -- DeMent noted that both are used when large amounts of the right kind of content is moved through the Internet.
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