Mark Fisher

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iOS and Windows Updates – Storming the University Campus Network in Welcome and Unwanted Ways

A university network administrator, on most days, walks around the campus with a knowing smile and quiet satisfaction, when passing students transfixed by an episode of Game of Thrones streaming on their mobile screens, knowing that all is right on the campus network.

That all changes when Apple iOS or Windows updates, like torrential floods, are unleashed across the globe.

The staggering wave of iOS9 updates that swept over university campus networks a couple weeks ago signals a new normal that can make even the most seasoned network administrator shudder. While not as large as iOS8, at 4.58 GB, iOS9 updates still represented a 1.3 GB file download per device. The number of these Apple devices continues to grow at an astonishing rate as Apple reported at the beginning of 2015 that it has sold over 1 billion iOS devices. Further, this iOS release is compatible with the widest range of Apple devices, at 19 vs. 10 with iOS8. Given these numbers, the rate of upgrade to this latest iOS version will be the fastest adoption of any Apple OS version to date. To make matters worse, the iOS upgrade triggers app updates which further compound the burden on your network.

The popularity of Apple devices among university students, combined with the weight of the iOS9 software upgrade and the small window of time between when it was released and students updated their devices, resulted in a wave of traffic that could easily overwhelm even the most robust university network. Every network administrator knows they must provide the campus IT infrastructure needed to support the faculty, researchers and students. A great campus network can be a recruiting tool. It creates an environment that facilitates learning, research and, at nights and on the weekends, provides entertainment for weary students. On the other hand, the onslaught of device OS upgrades, when they come, can bring the network to its knees and make the network administrator yearn for lower enrollment.

Given our growing number of university deployments, we want to provide data from real world deployments to show how an Open Cache can effectively address the new normal of frequent device OS updates that would otherwise disrupt campus network operations. In this post, we’ll show you how Open Caching can be an effective alternative to building a bigger campus network. We have data that shows how an Open Cache deployment takes the ‘shock of OS updates’ out of the system.

How Does Open Caching Protect My Network?

In short, Open Caching acts as a protective service which normalizes traffic across the campus network during extreme events that would otherwise result in significant spikes in volume and severely degraded service to end users. The Open Cache will automatically detect the onset of such an event, like an iOS upgrade or Windows Update, and react automatically to protect the network and its users.

We have cache performance snapshots from university deployments that help tell this story and bring the value of Open Caching to life. This real world data confirms the operational performance of how Open Cache systems respond when faced a flood of software update requests coming from devices across the campus network.

University Network – Open Caching protects the network and users from Apple iOS9 Updates

In the analytics view below, during the three day period between September 15th and the 17th, when iOS9 update activities ramped up, the average volume across this university network increased between 64% (412 Mbps) and 76% (483 Mbps) each day. In the analytics visual, you can see clearly that the Open Cache responded to the dramatic increase in requests for iOS9 software updates by serving more traffic from the cache. During this period of demand, the Open Cache handled 86%+ of all requests for iOS9 software downloads from Apple device clients across the university network.

The Open Cache protected the campus network and its users by effectively absorbing the shock of this aperiodic event through allocating onboard storage and compute resources to efficiently handle requests that would have otherwise represented extraordinary demands on the campus infrastructure. In other words, the Open Cache was able to create network capacity in a different form, as cache-out delivery, when needed. Once the event has passed, the Open Cache, acting autonomously, will automatically reallocate compute and storage resources to other tasks such as streaming video on demand from Amazon or live streams from WatchESPN.

University 1 – Apple iOS9 Updates – September 2015

College Network – Open Caching protects the network and improves QoE for users during Windows Updates

When Windows updates were released on September 10th, traffic across this college network increased by 103% relative to its average peak over the rest of the month, representing 1.357 Gbps of additional volume.

Peaktime Traffic Volume

In the analytics visual, you can see clearly that the Open Cache responded to the dramatic increase in requests for Windows software updates by serving more traffic from the cache. During this period of dramatically increased demand, the Open Cache handled 97.8% of all request for Windows Updates downloads from device clients across the college network.

College 3 – Windows Updates – September 2015

College Network – Open Caching improves QoE for users during Software Downloads

Open Caching improves the Quality of Experience for users during software downloads as well. From our deployments, we’ve captured data that shows a dramatic decrease in download time when software updates are delivered from the in-network Open Cache instead of an off-network upstream CDN or content providers site. This is particularly true for both iOS and Windows updates. An OS update that would take more than 1 hour to complete can require only 10 to 15 minutes when delivered from an on-network Open Cache. Further, this offload frees network resources for other applications to access. This means that OTT video, gaming and VoIP applications will not see the significant degradation in performance they would otherwise face without Open Caching.

College 4 – QoE – September 2015

The Perfect Storm – When Periodic and Aperiodic Software Downloads Accompany the Release of a Popular Title

The performance snapshot for September 17th is representative of an accelerating trend; the convergence of high volume events. In this case, we see typically high Netflix volume, accompanied by iOS, Windows and Playstation software updates. We saw the same thing last year during the iOS8 update, which was concurrent with a Patch Tuesday and the release of popular content on VoD streaming sites.

Cacheable Traffic

Open Caching – A new tool for network administrators to protect their university campus network

University network administrators are faced with new challenges that will test their ability to cost effectively build, operate and scale campus networks. Rapid growth of applications such as live and on-demand streaming video are placing increasing demands on the network. Many of these applications can be measured and forecast with some accuracy so the network administrator can plan network capacity accordingly. However, another challenge, software downloads, are quite different. Software downloads like Windows Updates can be periodic and somewhat predictable. Updates from Apple iOS devices are released with less predictability and can, therefore, drive extreme traffic spikes and be very difficult to manage. Thankfully, university network administrators have new tools, such as Open Caching, to deploy in response to these new and unpredictable demands.

We’ve collected enough real world data from university network deployments to confidently present the outcomes shown in this report. This operational report clearly makes the case for Open Caching as an effective and dependable tool for network operators to employ as they prepare their networks for the growing and inevitable onslaught of frequent and intense software downloads as part of the ‘new normal’ for campus networks around the world.