Some sample scenarios on how DWiNCE can be used to improve the efficiency of test execution is discussed here. A typical test setup for testing Access Point is shown in figure below.

Every Access Point (AP) has a limit on the number of wireless clients it can service. This is defined by the size of the Association Table and the ability of the Access Point to respond to a request by the wireless client. If the number of clients associated to the AP fills up the Association Table, the AP generally responds to a new request by sending Association or Re-association response frame with Status Code 17 (Association denied because the AP is unable to handle additional associated stations). AP may also send a Disassociation frame with reason code 5 (Disassociated because AP is unable handle all currently associated stations). Even if AP has a large table size, the processing power of the AP may not be enough to handle service requests from the wireless stations. Kardea’s DWiNCE solution can easily test these scenarios. Create a test case to emulate a large number of wireless clients. Execute the test and capture the wireless packets over the air. Whenever the AP reaches its capacity to handle more stations, further association of emulated clients to the AP will start failing. The response of the AP can be analyzed from the captured wireless packets.

A wireless station will remain connected to only one AP at any given time. If the station senses a weakening signal from the AP it is connected to, it will try to find a better AP and connect to it. The moving of the wireless station from one AP to another is termed as roaming. The station may or may not be able to inform the original AP that it is leaving. In many of the new generation products, the destination AP can inform the original AP about the station roam using Inter Access Point Protocol (IAPP). Kardea’s DWiNCE solution can simulate these roaming scenarios without physically moving your wireless device away from one AP and towards the second AP. Nor, do you need any hardware like attenuators, RF cables and boxes to set up a test bed. Create a wireless profile with the channel number set to that of the first AP. Make an exact copy of this wireless profile, but set the channel number to that of the second AP. With these two wireless profiles, make two test cases that are exactly same in all other respect. Use the same data profile for them. Combine the two test cases in a test suite and execute them. By emulating large number of clients in each test case, the ability of the WLAN to handle roaming of large number of wireless stations can be tested.

Security is the most important aspect of a wireless network. In IEEE 802.11 three types are defined: Open, WEP and WPA. In WEP and WPA we have different options for data encryption and authentication leading to a large number of scenarios to test. You can automate the security testing using DWiNCE by creating a suite of test cases. All your test scenarios will be executed by a single click and you can store it for future use or sharing it with other team members. If your AP supports multiple BSSID, on the same AP create the different WLAN with unique SSID and security setting you want to test. If your AP does not support multiple BSSID, you will have to use more than one AP, with each AP configured with unique SSID and security settings to be tested. On DWiNCE, typically you will create a wireless profile for each SSID and the corresponding security options as in the AP. Then create a test case of single client with a unique MAC address for each wireless profile. Combine them in a test suite and run it. The current version of DWiNCE will support open and WEP as security option.

One way a hacker can try to gain an unauthorized access to the network or confuse the WLAN is by spoofing the MAC address of an authorized client who is already connected to the wireless network. The person then uses that MAC address on his wireless client and tries to gain access and/or de-stabilize the network. A secure and robust WLAN should be able to detect such rogue clients and try to contain it. DWiNCE can be used to validate the reliability of such an Intrusion Detection System. Connect a regular wireless client to the AP. Use the same MAC address in the test case to emulate the fake client. Monitor the behavior of you network and see if the fake client emulated by DWiNCE is able to ping the network.

Typically feature/functional testing is done using two or three wireless devices. Testing of AP capabilities with large number of wireless devices is planned for a later stage of test cycle and not all feature/function are exercised in this larger setup. This creates a risk of finding serious bugs late in the game or even remaining undiscovered. Using multiple stations to exercise the feature improves the likelihood of finding bugs early. DWiNCE can be used to exercise this feature via emulated clients. Even if all the devices are not exercising the feature under test, loading the WLAN with a typical number of clients and traffic in background, improves the chance of finding complex issues early. DWiNCE can be used to create this background wireless network activity by associating the emulated clients on a different BSSID of the same AP. This not only improves the overall quality of the product shipped to the customer, but also reduces the risk to the program schedules.