Network Capacity Growth: Plan for Exponential Increases

Digital transformations can tax networks to the breaking point. Here's how to make sure your infrastructure is ready for the demands of new devices and digital curriculum.

• By Marie Bjerede, Keith R. Krueger
• 06/11/15

One megabit per second per student is the current “magic number” in school network design. It is the long-term goal set by the Federal Communications Commission (FCC) and originally established by the State Education Technology Directors Association (SETDA) as the 2017 goal for Internet capacity. It is about the same capacity per user offered in the most basic of cable plans, and an order of magnitude less than what many families need for modern Internet use. This “modern use” includes streaming video, interactive content and fast Web browsing by multiple family members simultaneously.

One megabit per second per student is also a number that only 15 percent of school districts can currently meet, according to CoSN's latest E-Rate and Infrastructure Survey. In fact, this modest broadband goal is so overwhelming to achieve that many districts cite the financial obstacle as the primary reason they don't embark on a digital transformation for their schools and their students.

Reaching this goal seems outrageously ambitious to many district IT and financial leaders, particularly those in large districts.

Do Schools Really Need That Much Bandwidth?

According to the CoSN Smart Education Networks by Design (SEND) initiative's work with leading districts, the answer is: absolutely!

School districts can get by for a long time with limited bandwidth and lackluster network design if they are not making the shift to the student-centered teaching and learning enabled by personal devices. But once a district commits to digital transformation, new demands are placed on their technological infrastructure, and those demands begin to grow non-linearly and will continue to do so for the foreseeable future.

The first phenomenon many districts encounter is that no matter how much bandwidth they provide, it's simply not enough. It often takes years for districts to reach a minimal level of capacity where the network itself is no longer the bottleneck for student access to the Internet and their cloud-based resources. Yet as the district adds capacity, student use of their devices explodes to take advantage of the new digital capacity and access to online resources. Often, the district will then take a look at the usage and decide to double the capacity the following year — once again with the same result. Student usage immediately swamps the network capacity.

During the planning process, it may often seem as though there is adequate network capacity, but this is an illusion. Students change their behavior and bandwidth needs surge as the network access allows. This goes on until all the other students try doing the same thing, and new bottlenecks develop. Students then back off their usage and wait until they have better connectivity available to them than at school. Likewise, teachers back off on the kinds of digital work they ask students to do in the classroom, since they don't want to waste instructional minutes on getting everyone logged on a creeping network. The network is used less, and so the capacity levels seem acceptable.

Successful districts monitor their networks carefully in order to determine when they need more capacity. They look at the average bandwidth usage, but also look carefully at peak loads. There are certain times of day — such as when classes start or end and all students are told to log on or off their devices and digital content at the same time — when there is always a spike in demand on the network.

A key question is this: How close does the spike come to 100 percent of the network's capacity? Does it get so high that teachers and students are at risk for backing off their technology usage? In North Carolina, for example, the state education network increases capacity to a district when they find that it exceeds 60 percent capacity more than 85 percent of the time.

Applying Moore's Law to Network Capacity

A second phenomenon becomes evident once districts have established sufficient capacity for their existing needs and are ready to plan for future growth. When districts embark on a digital transformation, their capacity requirements grow exponentially. This growth varies from district to district, but it is common to see growth of 60 percent every year. This translates to a doubling of network capacity every 18 months! As if there were a Moore's Law that applied to network capacity growth.

The implications of this growth are staggering. If a district develops a technology plan with the incredibly ambitious infrastructure refresh rate of three years, and they plan for a doubling of capacity over that time, they are underestimating their growth by 100 percent. This means that halfway through their technology initiative, they may have inadequate access points, cabling, routers, switches, firewalls, security appliances, filtering appliances and any other hardware that was intended to meet the district's needs for at least three years. The district is then faced with either limiting teaching and learning with technology or making new infrastructure investments far sooner than anticipated.

How can this growth be sustainable? Doesn't it ever slow down?

The current experience of districts involved in digital transformation suggests that at the very least, a slowdown won't be happening within the timeframe of current and planned infrastructure investments. If districts don't plan for exponential growth, they run a significant risk of making investments that will be obsolete well before they can afford to invest again. This is true both for school districts that are beginning their digital transformation and for those that have mature implementations. To use North Carolina as an example again, districts in their first years of 1-to-1 programs are seeing 60 percent annual growth, as is the well known leading district Mooresville Grade School District, which has provided laptops to every student for eight years.

What Is Driving This Growth?

In the early stages of digital transformation, the growth comes mainly from expanding the technology program. In 1-to-1 districts, new grade levels or more schools get devices each year. In BYOD districts, more and more students bring their own devices, with some districts now seeing three-plus devices per student.

There are also changes in the content that students are accessing. Digital curriculum is becoming larger than ever, requiring more bandwidth to transfer lessons to student devices. Many device operating systems are becoming more "chatty," sending lots of data across the network to keep the student devices synchronized with the cloud. Device management software adds functionality that requires the management software to connect frequently with the device. And even simple Web pages are becoming larger, with more content, which increases the bandwidth required for simple Web browsing.

As teaching and learning with technology become more mature in a district, there is often a dramatic shift toward student-centered and personalized learning. This shift, and the power it gives to students, families and teachers, is the highest good that comes from digital transformation, but it entails changes that increase student usage of the Internet, the need for rich digital resources and use of online communities of learning for students and educators.

Where will it end?

Not within our current horizon. The digital tools and resources that are available in support of transformative environments are still incredibly immature: We are barely at the beginning of what technology can eventually offer education. Consider the impact on capacity once content developers can securely offer meaningful, continual formative assessment embedded in game-based learning and immersive activities. Consider the impact once teachers (and especially students) have tools that allow them to not only extract data about their performance but to develop their own creative data visualizations. Consider the impact when students learn collaboratively in real time with other students anywhere in the world.

For now, and for the future as far as we can plan for it, digital transformation requires that districts plan carefully for exponential growth. The best way to address that growth is to build networks that are readily scalable, then carefully monitor usage in order to stay ahead of capacity demand. Many districts now have agreements with their service providers to be able to ratchet up Internet bandwidth at a moment's notice with only a phone call. Many have service-level agreements with third parties that call for a periodic refresh of all hardware to meet capacity demands.

But for those who are just beginning the transformation and who don't yet have real data to use for their predictions, there is a simple rule of thumb: Start with the goal of 100 Mbps per student, then plan for to double capacity every year and a half. This will prepare you for the new normal: constant, accelerating change.