Updated February 5, 2002
June 29, 2000
Products Affected
|
Product |
Comments |
|---|---|
|
PCI4810B |
Aironet 11Mbps DSSS PCI Adapter with 40-bit WEP |
|
PCI4820B |
Aironet 11Mbps DSSS PCI Adapter with 128-bit WEP |
|
PC4800B |
Aironet 11Mbps DSSS PC Card Adapter |
|
PC4810B |
Aironet 11Mbps DSSS PC Card Adapter with 40-bit WEP |
|
PC4820B |
Aironet 11Mbps DSSS PC Card Adapter with 128-bit WEP |
|
LM4800B |
Aironet 11Mbps DSSS PC Card Adapter without antenna |
|
LM4810B |
Aironet 11Mbps DSSS PC Card Adapter without antenna with 40-bit WEP |
|
LM4820B |
Aironet 11Mbps DSSS PC Card Adapter without antenna with 128-bit WEP |
|
AP4801B |
Aironet 11Mbps DSSS Access Point with 2 RP-TNC connectors |
|
AP4821B |
Aironet 11Mbps DSSS Access Point without 40-bit WEP and 2 integrated antennas |
|
AP4823B |
Aironet 11Mbps DSSS Access Point with 40-bit WEP and 2 RP-TNC connectors |
|
AP4810B |
Aironet 11Mbps DSSS Access Point with 40-bit WEP and 1 integrated antenna |
|
AP4820B |
Aironet 11Mbps DSSS Aceess Point with 128-bit WEP and 2 integrated antennas |
|
AP4822B |
Aironet 11Mbps DSSS Access Point with 128-bit WEP and 2 RP-TNC connectors |
|
AIR-PCM340 |
340 Series 11 Mbps DSSS PC Card Adapter |
|
PCM341 |
340 series 11Mbps DSSS PC Card Adapter with 40-bit WEP |
|
AIR-PCM342 |
340 series 11Mbps DSSS PC Card Adapter with 128-bit WEP |
|
PCM342US |
340 series 11Mbps DSSS PC Card Adapter with 128-bit WEP (US Version) |
|
AIR-LMC340 |
340 series 11Mbps DSSS PC Card Adapter without antenna |
|
AIR-LMC341 |
340 series 11Mbps DSSS PC Card Adapter with 40-bit WEP without antenna |
|
AIR-LMC342 |
340 series 11Mbps DSSS PC Card Adapter |
|
AIR-AP340E2C |
340 series 11Mbps DSSS AP with 2 integrated antennas |
|
AP340E2R |
340 series 11Mbps DSSS AP with 2 RP-TNC connectors |
|
AIR-AP341E2C |
340 series 11Mbps DSSS AP with 40-bit WEP and 2 integrated antennas |
|
AIR-AP341E2R |
340 series 11Mbps DSSS AP with 2 RP-TNC connectors |
|
AIR-AP341S1C |
340 series 11Mbps DSSS AP with 40-bit WEP and 1 integrated antenna |
|
AIR-AP342E2C |
340 series 11Mbps DSSS AP with 128-bit WEP and 2 integrated antennas |
|
AIR-AP342E2R |
340 series 11Mbps DSSS AP with 128-bit WEP and 2 RP-TNC connectors |
|
AIR-AP342E2RUS |
340 series 11Mbps DSSS AP with 128-bit WEP and 2 RP-TNC connectors (US Version) |
|
AIR-PCI340 |
340 series 11Mbps DSSS PCI Adapter |
|
AIR-PCI341 |
340 series 11Mbps DSSS PCI Adapter with 40-bit WEP |
|
AIR-PCI342 |
340 series 11Mbps DSSS PCI Adapter with 128-bit WEP |
Problem Description
Customers experience a loss of communication on their Wireless LAN when roaming beyond the 11Mbps coverage area.
Background
Auto Rate Shifting is an 802.11 defined Wireless LAN feature that enables users to increase coverage area beyond the 11Mbps coverage area by decreasing data rate. Most Cisco Aironet 340 Series customers design their Wireless LAN to provide full 11Mbps coverage, and tend not to take advantage of this feature.
The factory default setting is 11Mbps with automatic data rate shifting to the lower speeds: 5.5Mbps, 2Mbps, and 1Mbps.
Problem Symptoms
Customers who configure the radio to run at the lower speeds, or who anticipate rate shifting to the lower speeds, will not experience greater coverage (or range) than the 11Mbps coverage.
When the client roams beyond the 11Mbps coverage area, the rate shift down to 5.5Mbps, 2Mbps, and finally 1Mbps occurs almost instantaneously and does not provide any additional range. The user perception is that communication drops off immediately beyond the 11Mbps coverage area.
Workaround/Solution
Auto rate shifting is a hardware issue. Complete Access Point and Client Adapter replacement is required to enable this feature.
If you are experiencing this rate shifting issue, please contact the Technical Assistance Center (TAC) to process a return materials authorization (RMA).
For Cisco branded Access Points (AIR-AP34x) and PCI adapters (AIR-PCI34x) , the starting serial number enables auto rate shifting. Anything below these values will require a replacement.
Note:?Products with serial numbers containing -88- will not require a replacement.
For Cisco branded PC Cards (AIR-PCM34x and AIR-LMC34x), only those with the part number format 4xx-xxxxxx-006 will require a replacement.
Note:?The part number is located above the bar code.
|
Product Model Number |
Serial Number |
|---|---|
|
AIR-AP342E2C |
1EF99002524 |
|
AIR-AP341E2C |
1EC99001258 |
|
AIR-AP342E2R |
1EG99003637 |
|
AIR-AP341E2R |
1ED99001128 |
|
AIR-AP341S1C |
1EE99001247 |
|
AIR-AP340E2C |
1EA99001196 |
|
AIR-AP340E2R |
1EB99001165 |
|
AIR-AP342E2RUS |
1EJ99004336 |
|
AIR-PCI340 |
1CH99001342 |
|
AIR-PCI341 |
1CJ99001108 |
|
AIR-PCI342 |
1CK99002930 |
|
Product Model Number |
Serial Number |
|---|---|
|
AIR-PCM340 |
ends in -009 |
|
AIR-PCM341 |
ends in -009 |
|
AIR-PCM342 |
ends in -009 |
|
AIR-PCM342US |
ends in -009 |
|
AIR-LMC340 |
ends in -009 |
|
AIR-LMC341 |
ends in -009 |
|
AIR-LMC342 |
ends in -009 |
For the Aironet-branded products, all serial numbers and part numbers (for PC Cards) apply.
DDTS
To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.
|
DDTS |
Description |
|---|---|
|
Ap stays at 11mb rate until reaching max sensitivity |
For More Information
If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: