D-Link DWS-4026 Product Manual - Page 521

Software User Manual 12/10/09 D-Link Unified Access System Field Queue AIFS (Inter-Frame Space) cwMin (Minimum Contention Window) cwMax (Maximum Contention Window) TXOP Limit Table 337: QoS Settings (Cont.) Description Station EDCA Parameters Queues are defined for different types of data transmitted from station-to-AP: • Data 0 (Voice)-Highest priority queue, minimum delay. Time-sensitive data such as VoIP and streaming media are automatically sent to this queue. • Data 1(Video)-Highest priority queue, minimum delay. Time-sensitive video data is automatically sent to this queue. • Data 2 (best effort)-Medium priority queue, medium throughput and delay. Most traditional IP data is sent to this queue. • Data 3 (Background)-Lowest priority queue, high throughput. Bulk data that requires maximum throughput and is not time-sensitive is sent to this queue (FTP data, for example). The Arbitration Inter-Frame Spacing (AIFS) specifies a wait time for data frames. The wait time is measured in slots. Valid values for AIFS are 1 through 255. This parameter is used by the algorithm that determines the initial random backoff wait time (window) for data transmission during a period of contention for The value specified in the Minimum Contention Window is the upper limit (in milliseconds) of a range from which the initial random backoff wait time is determined. The first random number generated will be a number between 0 and the number specified here. If the first random backoff wait time expires before the data frame is sent, a retry counter is incremented and the random backoff value (window) is doubled. Doubling will continue until the size of the random backoff value reaches the number defined in the Maximum Contention Window. The value specified in the Maximum Contention Window is the upper limit (in milliseconds) for the doubling of the random backoff value. This doubling continues until either the data frame is sent or the Maximum Contention Window size is reached. Once the Maximum Contention Window size is reached, retries will continue until a maximum number of retries allowed is reached. Station EDCA Parameter Only (The TXOP Limit applies only to traffic flowing from the client station to the access point.) The Transmission Opportunity (TXOP) is an interval of time when a WME client station has the right to initiate transmissions onto the wireless medium (WM). This value specifies (in milliseconds) the Transmission Opportunity (TXOP) for client stations; that is, the interval of time when a WMM client station has the right to initiate transmissions on the wireless network. PEER SWITCH The Peer Switch Configuration feature allows you to send a variety of configuration information from one switch to all other switches. In addition to keeping the switches synchronized, this function allows you to manage all wireless switches in the cluster from one switch. The Peer Switch Configuration Request Status page provides information about the status of the configuration upgrade on the switches in the cluster. Document 34CSFP6XXUWS-SWUM100-D7 Configuring Advanced Settings Page 521