Cisco Cisco Aironet 340 Ethernet Bridges Fehlerbehebungsanleitung
Transmit Errors
Retries
This type of error provides a cumulative count of the number of times a frame was retransmitted because an
acknowledgment was not received.
acknowledgment was not received.
At times an ACK is not seen from the remote. Here are some common reasons:
The packet to be acknowledged is received with a CRC error.
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The ACK becomes corrupt in transit.
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Treat this issue as you would treat a CRC problem.
Another possibility is an improper configuration of the Distance parameter. The radio link between bridges
can be long. Therefore, the radio signal takes so long to travel between the radios that the delay on the link is
longer than the time the bridge waits for an ACK. The Distance parameter is used to adjust the various timers
used in the radio protocol to account for the extra delay. Refer to Using the Cisco Aironet 340 Series Wireless
Bridges for configuration details.
can be long. Therefore, the radio signal takes so long to travel between the radios that the delay on the link is
longer than the time the bridge waits for an ACK. The Distance parameter is used to adjust the various timers
used in the radio protocol to account for the extra delay. Refer to Using the Cisco Aironet 340 Series Wireless
Bridges for configuration details.
Max Retries/Frame
This error indicates the maximum number of times a frame was retransmitted. Excessive retries indicate a
poor quality radio link.
poor quality radio link.
Queue Full Discards
This error displays the number of times a packet was not transmitted due to excessive retries to the same
destination. Discards only occur if packets destined to this address take up more than their share of transmit
buffers.
destination. Discards only occur if packets destined to this address take up more than their share of transmit
buffers.
Queue Full Discards occur when traffic enters the bridge from the Ethernet faster than the bridge can forward
the traffic across the radio link. When the radio transmit queue fills up, packets are discarded.
the traffic across the radio link. When the radio transmit queue fills up, packets are discarded.
This problem occurs if the radio link is of poor quality. This means the effective throughput of the radio link
can be somewhat below 11 Mbps (due to CRCs and retries). When a high volume of traffic travels from the
Ethernet, the transmit buffers get full and discard frames.
can be somewhat below 11 Mbps (due to CRCs and retries). When a high volume of traffic travels from the
Ethernet, the transmit buffers get full and discard frames.
Holdoffs
Holdoffs indicate the number of times that the radio transmitter could not transmit because the receiver
detected the "carrier busy" message. Large numbers of holdoffs can occur due to many other Wireless LAN
devices that transmit in the area, or due to the presence of other devices, for example, cordless telephones, that
operate in the 2.4GHz range.
detected the "carrier busy" message. Large numbers of holdoffs can occur due to many other Wireless LAN
devices that transmit in the area, or due to the presence of other devices, for example, cordless telephones, that
operate in the 2.4GHz range.
Ethernet Error Statistics
The Ethernet Error Statistics Display provides a detailed summary of Ethernet errors. In order to access this
Ethernet Errors Statistics Display, select Menu > Statistics > Ethernet.
Ethernet Errors Statistics Display, select Menu > Statistics > Ethernet.