Solution Brief Seven Guidelines to Support Standardized Testing Using Wi-Fi to Enable Online Student Assessments
Introduction With a nearly $400 million dollar investment from the US Department of Education, school systems across the US are being urged to move their current standardized testing to online services to accurately and efficiently measure student achievement and growth. School IT departments have until the 2014-2015 school year to prep their networks for online assessments. Between the Smarter Balanced consortium and the PARCC (Partnership for Assessment of Readiness for College and Careers) alliance, many states have resources that provide guidelines to ensure accurate testing implementations, but the direction for network preparations are still a little unclear. See below for seven things you can do to prep your network for online testing. 1. Assess your Current Infrastructure and Capacity Capabilities Look at your current network design to determine whether your current network is prepared to support the density and throughput requirements necessary for online testing. Current guidelines from PARCC and Smarter Balanced recommend Internet bandwidth of100kbps per student, and 1Mbps per student internal bandwidth 1. Many IT administrators are investigating using tablets or Chromebooks, which lack Ethernet ports. Wi-Fi capacity will be a major consideration when preparing for online testing. Ensure wired infrastructure is prepared to support connected access points by confirming switch ports are at least 1Gbps and support 802.3af PoE, as well as capable of prioritizing traffic using standards-based Quality of Service (802.1p or DiffServ). 2. Implement Quality of Service Make sure your selected Wi-Fi infrastructure vendor supports standards-based Quality of Service to assure performance for connected students while taking the examinations. Wi-Fi may be the only choice for many schools that support tablets, Chromebooks, and other devices that lack an Ethernet port. Robust quality of service will allow an administrator to prioritize important applications, such as the online testing service, over background applications that may also be trying to use the Wi-Fi at the same time. In addition, if the Wi-Fi infrastructure supports marking packets as they leave the access points with standardsbased QoS such as 802.1p or DiffServ, the packets can continue to be prioritized throughout the wired infrastructure all the way to the gateway. 1 http://www.parcconline.org/sites/parcc/files/parcctechnologyguidelines2dot1_feb2013update.pdf
Seven Guidelines to Support Standardized Testing Figure 1: Context-based policies with Quality of Service defined per user 3. Plan for and Support High Density The number of devices and students may vary both with scheduled online assessments as well as daily classroom activity. Unlike wired network link indicators, Wi-Fi signal strength does not necessarily equal high performance. The Wi-Fi radio bandwidth is shared among all clients within range of one another on a particular channel, much like a legacy wired hub. This means high-density design and capacity planning must take into account the entire client population as well as spectrum capacity, channel utilization, interference, and frequency re-use in order to distribute the load effectively across the available spectrum. A smart Wi-Fi infrastructure will help plan with integrated planning tools to design and implement the access points, as well as account for high-density client requirements once the access points are in use. Look for features that do the following: Minimize co-channel interference Maximize spectral capacity by co-locating radios on different channels Band steer clients to optimize use of available spectral capacity Load balance clients between access points based on available airtime and load, application bandwidth, and latency requirements Suppress client probes and reduce probe responses Manipulate the basic data rate for management frames Figure 2: High Density Settings Copyright 2013, Aerohive Networks, Inc. 3
4. Set Up an Application Aware Enforcement Infrastructure One of the major challenges facing administrators as they look at online testing is assuring students are accessing the right content with the right devices. Application visibility and control gives the administrator the power to view exactly what applications users on the network are accessing, and then prioritize, de-prioritize, or even block applications so students can have an optimized and controlled experience while using the testing software. It is important to have a system that can do this based on context, so the policies can be granular based on the identity of the user (student taking the assessment versus the rest of the student population or faculty also using the network), device type and ownership (test device versus any device a user may bring in from home), location, and time of day. An access point with an integrated stateful firewall will make enforcing access to only the test application much easier as the decision can be made right at the edge rather than chancing a network hiccup that might allow misbehavior or access to unauthorized content before the traffic reaches the gateway firewall. Figure 3: Application Usage Information 5. Implement Service Level Assurance (SLA) for Clients Client performance is affected by many different variables, especially in a Wi-Fi environment. Service Level Assurance (SLA) for clients allows an administrator to define a minimum performance threshold for connected clients. This gives early visibility into coverage or capacity issues, and appropriate corrective actions can automatically be taken with each client that is not meeting its SLA. Remediation options include: Load balancing a client to another more available access point Band Steering a client to a spectrum with more availability capacity Automatically allocate additional airtime to clients not meeting the SLA SLA visibility, fault-recovery actions, and in-depth analysis will allow the network administrator to see the big picture while the Wi-Fi platform does all of the work. 4 Copyright 2013, Aerohive Networks, Inc.
Seven Guidelines to Support Standardized Testing Figure 4: Real-time Service Level Assurance with Automatic Remediation 6. Choose a System that Grows with Requirements In order to assure ongoing success, make sure the Wi-Fi infrastructure you choose to support the online testing can grow and scale along with your student base and client requirements. Designing a network for the test requirements today can be limiting if next year s requirements demand more from the infrastructure. A cooperative control infrastructure will allow you to add, move, or even remove access points as needed without any concern for reaching the maximum capacity of an unnecessary and expensive WLAN controller. Make sure the access points also support automatic meshing and bridging to extend networks wherever access is required, not just where Ethernet ports are available. Figure 5: Start small and grow with cooperative control Copyright 2013, Aerohive Networks, Inc. 5
7. Centralize Management and Troubleshooting In the midst of online testing, it may not be possible for an administrator to run to every location to help troubleshoot issues that may arise. Centralized management and troubleshooting will greatly simplify managing a next-generation wireless network prepared for online testing. A unified policy that defines access for both wired and wireless users within a single workflow is necessary to create a cohesive experience for connected clients, and a unified dashboard that can display information about connected users, managed devices and clients, and provide reporting information will also make managing the network much easier for a central IT team. Figure 6: Real-time dashboard and alerts In the current era of accountability in education, data from standardized assessments frequently serves as the principal source of evidence for evaluating the success of districts, schools, and even the teaching methods of individual educators. To accurately evaluate our nation s students, and thereby contribute to improving our nation s education systems, testing has to be reliable and repeatable. Having a network prepared for the myriad of connected devices, increasing student population, and ever changing requirements is necessary to ensure online testing can truly measure the performance of our students and accurately reflect what we can do to improve our nation s future. For more information on building a network ready for online testing using Aerohive products, please contact us at +1-866-365-9918, join our community at http://community.aerohive.com, or check out a free demo at http://www.aerohive.com/build-your-network. 6 Copyright 2013, Aerohive Networks, Inc.
About Aerohive People want to work anywhere; on any device, and IT needs to enable them -- without drowning in complexity or compromising on security, performance, reliability or cost. Aerohive's mission is to Simpli-Fi these access networks with a cloud-enabled, self-organizing, service-aware, identity-based infrastructure that includes innovative Wi-Fi, VPN, branch routing and switching solutions. Aerohive was founded in 2006 and is headquartered in Sunnyvale, Calif. The company's investors include Kleiner Perkins Caufield & Byers, Lightspeed Venture Partners, Northern Light Venture Capital, New Enterprise Associates, Inc. (NEA) and Institutional Venture Partners (IVP). For more information, please visit www.aerohive.com, call us at 408-510-6100, follow us on Twitter @Aerohive, subscribe to our blog, join our community or become a fan on our Facebook page. Corporate Headquarters International Headquarters Aerohive Networks, Inc. Aerohive Networks Europe LTD 330 Gibraltar Drive The Court Yard Sunnyvale, California 94089 USA 16-18 West Street Phone: 408.510.6100 Farnham, Surrey, UK, GU9 7DR Toll Free: 1.866.918.9918 + 44 (0) 1252 736590 Fax: 408.510.6199 Fax: + 44 (0) 1252 711901 info@aerohive.com www.aerohive.com