As final step when testing the performance of the WLAN, ensure that multiple users can use applications on the network. The goal here is to verify that the WLAN can continue to satisfy all requirements while a typical (and maximum) number of users are using the system. The best way to test load on the network is with actual users and client devices. In some cases, however, you may need to resort to simulation as explained later in this chapter. For example, with a wireless IP phone system, make use of multiple wireless IP phones throughout the facility. Ideally, distribute and use the phones in a similar manner as they will actually be used when operational. Find volunteers or actual users to help you with these tests. You can give them each a phone, instruct them on how to use it, and have them initiate calls with others. To simplify testing, you can start by having the group of callers place calls from the same location, and then have them separate uniformly throughout the facility while continuing voice conversations and monitoring voice quality. If requirements in parts of the facility specify a need for higher capacity, have an appropriate number of test users make use of the phones from that area. Again, strive to test the system as users will use it. While performing the load tests, monitor the system using network analyzers or system management tools, if available. Also, be sure to receive feedback from the users actually using the devices, and identify any related issues. If problems arise, note the applicable time and location in the facility where the problem occurred. Doing so makes it easier when looking through the results of the monitoring tools to identify the underlying problems.