Cisco WAP200 Administration Guide - Page 54

Chapter 2 How it works Chapter 2 RF performance Use the following features to help improve the performance of the wireless network. Client station data rate limits The WAP-200 provides settings for controlling the minimum and maximum client data rates on each VSC. These rates are advertised in the 802.11 beacon, sent in response to wireless probes, and specified in the negotiated rate of the association response. The primary application for these settings is to enable performance optimization across the wireless network. For example, if the minimum data rate is set to 6 mbps, a client with a weak signal (that may only be able to associate at 1 Mbps) is prevented from doing so. If that same client was allowed to associate successfully, the overall performance of the network would be compromised downwards for all clients. By preventing the association, clients with more powerful signals are able to perform at their optimal capability. The following two settings are available when you define an SSID for a VSC. • Minimum rate: Sets the minimum transmission rate that client stations can use when communicating with the VSC. Client stations that are operating at a rate that is slower than this setting will be able to associate with the WAP-200 but will not be able to send or receive data. For example, if the minimum rate is set to 6 mbps and a client is not close enough to reach this rate, it will still see the WAP-200, but all transmissions will time out. Note: Increasing the minimum rate effectively reduces the cell size of the wireless network, since as the distance from the WAP-200 increases the data rate decreases. Note: Some wireless client stations may refuse to associate with the WAP-200 if the basic rates for the current operating mode are not supported. For example, if the minimum data rate is set to 6 mbps for 802.11b, this is above the mandated basic rates of 1 and 2 mbps, and may cause some clients to refuse the association. • Maximum rate: Sets the maximum transmission rate that clients stations can use when communicating with the VSC. Client stations that support higher rates will negotiate this value as their limit when associating to the WAP-200. Multicast rate limit The WAP-200 provides control of the multicast rate on a per-radio basis (on the Wireless > Radio page under Multicast Tx rate). By default this is set to the lowest rate for the current wireless mode. If there is a lot of multicast traffic on your network, raising the multicast rate can improve throughput. Note: If you raise the multicast rate, client stations that do not support the new rate will not receive the multicast data. 54