Alvarion BreezeACCESS VL 5.4, System Manual

Page: 79 / 157

Operation and Administration
5-19
Wireless Link Counters
The unit submits data frames received from the Ethernet port to the
internal bridge, as well as self-generated control and wireless management
frames. After a unicast data data frame is transmitted, the unit waits for
an acknowledgement (ACK) message from the receiving unit. Some control
and wireless management frames, as well as broadcast and multicast
frames sent to more than one unit, are not acknowledged. If an ACK is not
received after a predefined time, which is determined by the
Acknowledge
Time Limit parameter, the unit retransmits the frame until an ACK is
received. If an ACK is not received before the number of retransmissions
has reached a maximum predefined number, which is determined by the
Number of Retransmissions parameter, the frames are dropped.
The Wireless Link Counters include the following statistics :
♦
Total transmitted frames to wireless: The number of frames
transmitted to the wireless media. The total includes one count for
each successfully transmitted unicast frame (excluding
retransmissions), and the number of transmitted multicast and
broadcast frames, including control and wireless management frames.
There are also separate counters for the following:
™
Beacons (AU only)
™
Other Management frames (excluding Beacons in AU)
™
Data frames, including multicast/broadcast data frames and
successfully transmitted unicast data frames (excluding
retransmissions).
™
Total Transmitted Unicasts, including all unicast frames
successfully transmitted to the wireless media, excluding
retransmissions. This count is useful for calculating the rates of
retransmissions or dropped frames, since only unicast frames are
retransmitted if not acknowledged.
♦
Total submitted frames (bridge): The total number of data frames
submitted to the internal bridge for transmission to the wireless media.
The count does not include control and wireless management frames,
or retransmissions. There are also separate counts for each priority
queue to which the frames were routed, which are Low, Mid and High
(currently the High queue is not used for data frames).
♦
Frames dropped (too many retries): The number of dropped frames,
which are the frames unsuccessfully retransmitted until the maximum
permitted number of retransmissions without being acknowledged.
This count includes dropped data frames as well as dropped control
and wireless management frames.
♦
Total retransmitted frames: The total number of retransmissions,
including all unsuccessful transmissions and retransmissions.