3Com 3CRWX440095A, 3CRWX120695A manual Managed Access Point Commands

272CHAPTER 9: MANAGED ACCESS POINT COMMANDS

Usage — A retransmission is a packet sent from a client to a MAP radio that the radio receives more than once. This can occur when the client does not receive an 802.11 acknowledgement for a packet sent to the radio.

If the radio receives only a single copy of a packet that is transmitted multiple times by a client, the packet is not counted by the radio as a retransmission. For example, if a packet is corrupted and the radio does not receive it, but the second copy of the packet does reach the radio, the radio does not count the packet as a retransmission since the radio received only one recognizable copy of the packet.

The interval is 1000 packets. If more than the specified percentage of packets within a group of 1000 packets received by the radio are retransmissions, the radio increases power.

When the percentage of retransmissions exceeds the max-retransmissionsthreshold, the radio does not immediately increase power. Instead, if the data rate at which the radio is sending packets to the client is above the minimum data rate allowed, the radio lowers the data rate by one setting. If the retransmissions still exceed the maximum allowed, the radio continues to lower the data rate, one setting at a time, until either the retransmissions fall within the allowed percentile or the minimum allowed data rate is reached.

If the retransmissions still exceed the threshold after the minimum allowed data rate is reached, the radio increases power by 1 dBm. The radio continues increasing the power in 1 dBm increments until the retransmissions fall below the threshold.

After the retransmissions fall below the threshold, the radio reduces power by 1 dBm. As long as retransmissions remain below the threshold, the radio continues reducing power in 1 dBm increments until it returns to its default power level.

A radio also can increase power, in 1 dBm increments, if a client falls below the minimum allowed data rate. After a radio increases power, all clients must be at the minimum data rate or higher and the maximum retransmissions must be within the allowed percentile, before the radio begins reducing power again.