Performing Diagnostics
This chapter explains how to use ACU to perform user-level diagnostics.
The following topics are covered in this chapter:
•Overview of ACU Diagnostic Tools
•Setting Signal Strength Display Units
•Viewing the Status of Your Client Adapter
•Viewing Statistics for Your Client Adapter
Overview of ACU Diagnostic Tools
The ACU diagnostic tools enable you to assess the performance of your client adapter within the wireless network. These tools perform the following functions:
•Display your client adapter's current status
•Display statistics pertaining to your client adapter's transmission and reception of data
Setting Signal Strength Display Units
Follow these steps to specify the units used to display signal strength on the ACU Status window.
Step 1 Double-tap the ACU icon or select Start > Programs > Cisco > ACU. The Profiles window appears.
Step 2 Tap the Options button. The ACU Options window appears (see Figure 7-1).
Figure 7-1 ACU Options Window
Step 3 Select one of the following options for Signal Strength Display Units:
•Percent (%)—Displays the signal strength as a percentage. This is the default setting.
•dBm—Displays the signal strength in decibels with respect to milliwatts.
Step 4 Tap OK to save your changes.
Viewing the Status of Your Client Adapter
Follow these steps to view the current status of your client adapter.
Step 1 From the Profiles window, tap the Status tab. The Status window appears. Figure 7-2 shows the Status window with the signal strength values displayed as percentages, and Figure 7-3 shows the same window with the signal strength values displayed in decibels with respect to milliwatts (dBm).
Figure 7-2 Status Window (with Signal Strength as a Percentage)
Figure 7-3 Status Window (with Signal Strength in dBm)
Table 7-1 interprets each element of the Status window.
Table 7-1 Client Adapter Status
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|
The first line of the Status window |
Indicates the operational mode of your client adapter and the name of any associated access point. Value: Not Associated, Associated, Authenticated, or Ad Hoc Mode Note The access point name is shown only if the client adapter is in infrastructure mode and Aironet Extensions are enabled (on access points running Cisco IOS release 12.2(4)JA or later). |
Associated Access Point MAC Address |
The MAC address of the access point to which your client adapter is associated. It is shown only if the client adapter is in infrastructure mode. Note This field displays the MAC address of the access point's Ethernet port (for access points that do not run Cisco IOS) or the MAC address of the access point's radio (for access points that run Cisco IOS). The MAC address of the Ethernet port on access points that run Cisco IOS is printed on a label on the back of the device. |
Associated Access Point IP Address |
The IP address of the access point to which your client adapter is associated. It is shown only if the client adapter is in infrastructure mode, the access point was configured with an IP address, and Aironet Extensions are enabled (on access points running Cisco IOS Release 12.2(4)JA or later). Note If Aironet Extensions are disabled, the IP address of the associated access point is shown as 0.0.0.0. |
Signal Strength |
The signal strength for all received packets. The higher the value and the more green the bar graph is, the stronger the signal. The histogram below the bar graph provides a visual interpretation of the current signal strength. Differences in signal strength are indicated by the following colors: green (strongest), yellow (middle of the range), and red (weakest). Range: 0 to 100% or -95 to -45 dBm |
Signal Quality |
The signal quality for all received packets. The higher the value and the more green the bar graph is, the clearer the signal. The histogram below the bar graph provides a visual interpretation of the current signal quality. Differences in signal quality are indicated by the following colors: green (highest quality), yellow (average), and red (lowest quality). Range: 0 to 100% Note This setting appears only if you selected signal strength to be displayed as a percentage. See the "Setting Signal Strength Display Units" section for information. |
Noise Level |
The level of background radio frequency energy in the 2.4-GHz band. The lower the value and the more green the bar graph is, the less background noise present. Range: -100 to -45 dBm Note This setting appears only if you selected signal strength to be displayed in dBm. See the "Setting Signal Strength Display Units" section for information. |
Overall Link Quality |
The client adapter's ability to communicate with the access point, which is determined by the combined result of the adapter's signal strength and signal quality. Value: Not Associated, Poor, Fair, Good, Excellent Note This setting appears only if you selected signal strength to be displayed as a percentage. See the "Setting Signal Strength Display Units" section for information. |
Signal to Noise Ratio |
The difference between the signal strength and the current noise level. The higher the value, the better the client adapter's ability to communicate with the access point. Range: 0 to 90 dB Note This setting appears only if you selected signal strength to be displayed in dBm. See the "Setting Signal Strength Display Units" section for information. |
Transmit Power |
The power level at which your client adapter is currently transmitting. The maximum level is dependent upon your country's regulatory agency. Value: 1, 5, 20, 30, 50, or 100 mW Note Refer to the Transmit Power parameter in Table 5-1 for information on setting the client adapter's power level. |
Link Speed |
The rate at which your client adapter is currently transmitting data packets. Value: 1, 2, 5.5, or 11 Mbps |
Channel Set |
The regulatory domain for which your client adapter is currently configured, such as North America. This value is not user selectable. Note Refer to Appendix D, for a list of channel identifiers, channel center frequencies, and regulatory domains for each channel. |
MAC Address |
The MAC address assigned to your client adapter at the factory. |
Encryption |
Indicates the type of encryption that is being used for data packets. Value: None, WEP, Cisco TKIP, or WPA TKIP Note Refer to the "Overview of Security Features" section for details on these encryption types. |
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|
None |
Data encryption is disabled. |
WEP |
Static or dynamic WEP is enabled, but neither MMH MIC nor WPA is enabled. |
Cisco TKIP |
MMH MIC is enabled. |
WPA TKIP |
WPA is enabled. |
Message Integrity Check (MIC) |
Indicates whether your client adapter is using message integrity check (MIC) to protect packets sent to and received from the access point. MIC prevents bit-flip attacks on encrypted packets. During a bit-flip attack, an intruder intercepts an encrypted message, alters it slightly, and retransmits it, and the receiver accepts the retransmitted message as legitimate. Note MIC is supported automatically by the client adapter's driver, but it must be enabled on the access point. Value: None, MMH, or Michael |
|
|
None |
MIC is disabled. |
MMH |
MIC is enabled and is being used with Cisco TKIP. |
Michael |
MIC is enabled and is being used with WPA TKIP. |
Current IP Address |
The IP address of the client adapter. If your Windows CE device is set up to obtain an IP address from a DHCP server, you can press the Renew button to initiate a release and renew of the IP address. Note This parameter and the Renew button appear only on PPC 2002, PPC 2003, HPC 2000, and CE .NET devices. |
Driver Version |
The version of the client adapter driver that is installed on your Windows CE device. |
Firmware Version |
The version of the firmware that is currently running on your client adapter. |
Step 2 Tap OK to exit the Status window.
Viewing Statistics for Your Client Adapter
ACU enables you to view statistics that indicate how data is being received and transmitted by your client adapter. It also shows message integrity check (MIC) statistics if your client adapter's driver supports MIC and MIC is enabled on the access point.
Note The receive and transmit statistics are host statistics. That is, they show packets and errors received or sent by the Windows CE device. Link status tests from the access point or ACU site survey tool are performed at the firmware level; therefore, they have no effect on the statistics shown by the Statistics window.
Follow these steps to view your client adapter's statistics.
Step 1 From the Profiles window, tap the Statistics tab. The Receive Statistics window appears (see Figure 7-4).
Figure 7-4 Receive Statistics Window
The statistics are calculated as soon as your client adapter is started.
Table 7-2 describes each receive statistic that is displayed for your client adapter.
Table 7-2 Receive Statistics
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|
Multicast Packets |
The number of multicast packets that were received successfully. |
Broadcast Packets |
The number of broadcast packets that were received successfully. |
Unicast Packets |
The number of unicast packets that were received successfully. |
Bytes Received |
The number of bytes of data that were received successfully. |
Beacons Received |
The number of beacon packets that were received successfully. |
PLCP CRC Errors |
The number of times the client adapter started to receive an 802.11 Physical Layer Convergence Protocol (PLCP) header but the rest of the packet was ignored due to a cyclic redundancy check (CRC) error in the header. Note CRC errors can be attributed to packet collisions caused by a dense population of client adapters, overlapping access point coverage on a channel, high multipath conditions from bounced signals, or the presence of other 2.4-GHz signals from devices such as microwave ovens, wireless handset phones, etc. |
MAC CRC Errors |
The number of packets that had a valid 802.11 PLCP header but contained a CRC error in the data portion of the packet. Note CRC errors can be attributed to packet collisions caused by a dense population of client adapters, overlapping access point coverage on a channel, high multipath conditions from bounced signals, or the presence of other 2.4-GHz signals from devices such as microwave ovens, wireless handset phones, etc. |
Up Time (hh:mm:ss) |
The amount of time (in hours:minutes:seconds) since your client adapter was started. If the client adapter has been running for more than 24 hours, the time is displayed in days, hours:minutes: seconds. |
Step 2 To view the transmit statistics for your client adapter, tap the arrow in the Category drop-down menu and select Transmit Stats. The Transmit Statistics window appears (see Figure 7-5).
Figure 7-5 Transmit Statistics Window
Table 7-3 describes each transmit statistic that is displayed for your client adapter.
Table 7-3 Transmit Statistics
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|
Multicast Packets |
The number of multicast packets that were transmitted successfully. |
Broadcast Packets |
The number of broadcast packets that were transmitted successfully. |
Unicast Packets |
The number of unicast packets that were transmitted successfully. |
Bytes Transmitted |
The number of bytes of data that were transmitted successfully. |
Packets Retry Long |
The number of normal data packets that were retransmitted. |
Packets Retry Short |
The number of request-to-send (RTS) packets that were retransmitted. |
Packets Max Retries |
The number of packets that failed to be transmitted successfully after exhausting the maximum number of retries. |
Up Time (hh:mm:ss) |
The amount of time (in hours:minutes:seconds) since your client adapter was started. If the client adapter has been running for more than 24 hours, the time is displayed in days, hours:minutes: seconds. |
Step 3 To view the MIC statistics for your client adapter, tap the arrow in the Category drop-down menu and select MIC Stats. The MIC Statistics window appears (see Figure 7-6).
Note The MIC Stats option is available only if your client adapter's driver supports MIC and only if MIC is enabled on the access point.
Figure 7-6 MIC Statistics Window
Table 7-4 describes each MIC statistic that is displayed for your client adapter.
Table 7-4 MIC Statistics
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|
Packets MIC OK |
The number of packets that were received successfully with a valid MIC. |
Packets No MIC |
The number of packets that were discarded due to no MIC being found. |
Packets Incorrect MIC |
The number of packets that were discarded due to an incorrect MIC value. |
Packets No MIC Seed |
The number of packets that were discarded due to no MIC seed being received. |
Packets Wrong MIC Seq |
The number of packets that were discarded due to the MIC sequence number being wrong. |
Step 4 Tap OK to exit the Statistics window.