WLAN Access Point: 10 Crucial Capabilities and How to Test for Them
Today’s wireless local area networks (WLAN) access points are much more than simple wireless routers. Vendors are offering affordable high-end devices with powerful features inclusive of the application-centric quality of service, enterprise-grade security, and traffic visualization that are integral to efficient IT operations.
By understanding these features better, you can improve quality of service and save precious hours of lost productivity due to Wi-Fi issues.
10 CRUCIAL CAPABILITIES OF MODERN WLAN ACCESS POINT
When purchasing a new WLAN access point for an enterprise or public facility, make sure your access point is able to:
- Provide flawless access and good signal strength
- Scale to support the required capacity of users and application traffic. Modern access points have the capacity to support larger-scale enterprise deployments in increasingly mission-critical environments, from hospital wards, to power and water utilities, to traffic-management and public transportation systems.
- Load-balance usage volumes between access points. Modern access points have “admission control”—they can identify the bandwidth requirements of currently connected devices; if there is not enough bandwidth for a new device to connect, the access point will reject new connections and allow them to roam to another access point. Even if the user limit is, say, 256, the device is intelligent enough to recognize that a hundred users are depleting its bandwidth and turn away the hundred-and-first user, routing that user to another access point with higher session capacity and lower total traffic load.
- Adapt to changes in your physical environments: Modern access points take into account changes to walls, furniture, and relocation of the access point itself and optimize to provide maximum service quality and reliability enterprise users expect.
- Provide the appropriate level of security for your organization: Ensure that your device supports the latest authentication and encryption mechanisms.
- Provide good quality of service to new and old devices: Old devices tend to operate at lower speeds and naturally get a smaller share of network capacity. WLAN access points can compensate by allocating more bandwidth to older devices or giving priority to new and more efficient devices. This is known as “airtime fairness.”
- Enable visualization and monitoring: Access points can show what is going on in the wireless network and identify problems. Some access points have a dedicated radio just for monitoring. They can provide visibility into what is happening on the network—what types of devices are connected, their capabilities and configurations, what they are doing on the network. This can provide important insights into bring your own device (BYOD) devices and the mission-critical applications they run. The Information Technology (IT) department does not have control over these devices, so WLAN monitoring can be an excellent way to gather data about them on a daily basis. Monitoring can also be important to prevent security issues such as man-in-the-middle attacks. This level of visibility can show a network operator which access points mobile devices are connecting to and detect an additional, unauthorized AP that might be operated by an attacker.
- Provide analytics about network usage and application bandwidth consumption.
- Define policies promoting important traffic and demoting or blocking less important or unwanted traffic—for example, allocating more bandwidth to the CEO’s laptop, or preventing employees from using the Netflix app on the wireless network. A modern access point allows you to apply network policies based on type of traffic, (e.g., YouTube), and specific users.
- Support cloud-based control of all access points in your organization, even across multiple physical locations. Modern WLAN access points can simply be plugged in, and they automatically connect and configure themselves together with other access points in the same facility. A central cloud dashboard shows all your WLAN access points across one or more physical location, enabling central configuration and management.
HOW DO YOU KNOW WHAT YOU'RE GETTING?
The bigger your organization and the faster you grow, the more you will invest in WLAN access points and wireless infrastructure to support more employees and visitors to your facilities. Whether you are buying 10, 20, or 100 access points, you should test them first to see that the crucial capabilities are working properly and that you are getting highest level of reliability, performance, and enterprise-grade features that are needed to best support your enterprise IT needs.
You can perform a number of basic tests yourself with freely available off-the-shelf tools to validate some access point capabilities. These standard tests, however, will only stress only a few of the thousands of needed key performance indicators (KPIs) and functionalities present in a modern day enterprise-grade access point.
The rest of this document describes what is possible to test yourself and with specialized WLAN test tools provided by Ixia®.
TESTING THE WLAN ACCESS POINT: DO IT YOURSELF
These are some of the Access Point capabilities that you can test yourself, at least partially, with no special equipment or expertise:
CAPABILITY #1: FLAWLESS ACCESS AND SIGNAL STRENGTH
A simple test: Activate only one access point and make sure that several Wi-Fi enabled devices are able to connect to it and receive good signal strength from different locations around the facility.
CAPABILITY #2: CAPACITY
A simple test: Find a time when the office or facility is relatively full. Invite everyone present to a conferencing session (using a tool like WebEx or GoToMeeting). As new users connect, observe the video and voice quality throughout the conferencing session for all users.
CAPABILITY #5: QUALITY OF SERVICE FOR NEW AND OLD DEVICES
A simple test:
- Download a free program called Iperf.
- Install the server on a laptop on the wired network and the client on a few newer and older mobile devices.
- Run the following command from each of the client devices (sends test traffic consuming 5MB of bandwidth): iperf -c 192.xxx.xxx.xxx -u -b 5m
- Iperf will show output indicating the result of the test. The output should look like something like this: Server Report: 0.0-10.0 sec xx MBytes 1.9 xbits/sec 0.167 ms 49/69507 (0.07%)
- “Mbits/sec” is the actual bandwidth your device got from the WLAN access point.
- See how much bandwidth is allocated to older devices versus newer devices.
CAPABILITY #9: POLICY MANAGEMENT
A simple test:
- Open a browser on a mobile device, connect to Wi-Fi only and surf to a web page.
- Consult the WLAN access point documentation to see how to block port 80 on all your access points.
- Once port 80 is blocked, refresh the website on the device. You should get an error saying the site is not available.
WHAT CAN'T YOU TEST?
- Flawless access and good signal strength: Difficult to test how the access point will function with different types of client devices and usage conditions.
- Scales to support the required capacity: Difficult to perform a realistic test of maximum capacity. In the simple test you are limited to the number of devices available at a given moment.
- Ability to load-balance usage volumes: Difficult to perform a realistic test, requires emulating realistic user traffic.
- Ability to adapt to changes in physical environment: Difficult to perform a realistic test without recreating interference characteristic to the real-world physical environment.
- Appropriate level of security: Difficult to perform a realistic test without simulating an attack and seeing how the system behaves—or at least verifying compliance to security protocols.
- Visualization and monitoring: Difficult to test if the visualization and statistics shown are accurate.
- Analytics: Difficult to test if analytics data is accurate.
- Policy management: Difficult to test advanced policies, as this requires emulating user traffic with real applications, numerous user activities, and different mobile connected devices.
ADVANCED WLAN TESTING MADE SIMPLE
Ixia is the leader in Wi-Fi testing and WLAN network planning. The industry’s premier Wi-Fi test solution, Ixia’s IxVeriWave™ represents the gold standard in evaluating Wi-Fi performance and site readiness. The world’s leading WLAN infrastructure and mobile device manufacturers, service providers, system integrators, and enterprises use IxVeriWave to measure and optimize performance, reliability, and scalability throughout the product development lifecycle.
An important part of this testing is validating how access points support each of the 10 capabilities listed above. For example, we can simulate network traffic to test the maximum capacity of an access point, test load balancing and roaming behavior, simulate network interference, and measure the impact on users.
As you saw above, it is difficult to perform even a basic test of WLAN access point capabilities on your own. IxVeriWave makes it easy to comprehensively test a WLAN access point’s functions and components by simulating real-world conditions and measuring performance:
- Measures radio transmitter and receiver quality under a variety of ideal and real-world test conditions.
- Exercises the access point’s processor and packet buffers by running full line rate throughput tests to see if the access point can receive, process, and transmit large amounts of data.
- Tests the client association manager by connecting hundreds of client devices to the access point and making sure they can connect, disconnect, send and receive traffic.
- Tests the TCP/IP stack and measures the access point’s ability to handle web traffic.
- Tests quality of service on the access point by generating different types of traffic with different quality of service settings. This lets you check the level of performance for each device and each type of traffic with your access points.
- Fully tests the policy engine on the access point by creating many different policies (blocking or preferring different types of traffic) and then sending relevant traffic. For example, with IxVeriWave you can automatically set a policy to block P2P traffic, then simulate P2P traffic and make sure it does not get forwarded.
- Tests the client session manager on the access point to check roaming of clients between WLAN cells
- Tests the radio resource management capability of the access point: IxVeriWave generates different types of interference and checks the access point’s ability to operate uninterrupted
- Tests the authentication and encryption mechanisms supported on the access point, and ensures traffic is encrypted properly in all use cases
- Tests standards compliance for dynamic frequency selection (DFS) and Federal Communications Commission (FCC) radar
See how IxVeriWave can validate access point features and capabilities, saving money and reducing ongoing WLAN maintenance.