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Table Of Contents
Troubleshooting the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G
Resolving Startup and Connectivity Problems
Symptom: Incomplete Startup Process
Symptom: No Association to Cisco Aironet Access Points
Verifying Access Point Settings
Symptom: No Registration to Cisco Unified Communications Manager
Registering the Phone with Cisco Unified Communications Manager
Verifying TFTP Server Settings
Verifying Cisco Unified Communications Manager and TFTP Service Status
Creating a New Configuration File
Resolving Voice Quality and Roaming
Symptom: Cisco Unified Wireless IP Phone Resets Unexpectedly
Verifying Access Point Settings
Identifying Intermittent Network Outages
Verifying Voice VLAN Configuration
Verifying that the Phones Have Not Been Intentionally Reset
Eliminating DNS or Other Connectivity Errors
One-Way Audio During a Connected Call
Symptom: Improper Roaming and Voice Quality or Lost Connection
Voice Quality Deteriorates While Roaming
Delays in Voice Conversation While Roaming
Phone Loses Connection with Cisco Unified Communications Manager While Roaming
Phone Does Not Roam Back to Preferred Band
Monitoring the Voice Quality of Calls
General Troubleshooting Information
Troubleshooting Tips for the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G
Logging Information for Troubleshooting
Using the Trace Logs on the Unified IP Phone
Erasing the Local Configuration
Troubleshooting the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G
This chapter provides information that can assist you in troubleshooting your Cisco Unified Wireless IP Phone. It contains the following sections:
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Resolving Startup and Connectivity Problems
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For additional troubleshooting information, you can see the Cisco Unified Communications Manager Troubleshooting Guide.
Resolving Startup and Connectivity Problems
After installing a Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G in your network and adding it to Cisco Unified Communications Manager Administration, the phone should start up as described in the "Understanding the Phone Startup Process" section on page 3-17. If the phone does not start up properly, see the following sections for troubleshooting information:
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Symptom: Incomplete Startup Process
When an IP Phone connects to the wireless network, the phone should go through its normal startup process and the phone screen should display information. If the phone does not complete the startup process, the cause might be due to low RF signal strength, network outages, a dead battery in the phone, or the phone might not be functional.
To determine whether the phone is functional, follow these suggestions to systematically eliminate these potential problems:
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If, after attempting these solutions, the phone still does not start up, contact a Cisco technical support representative for additional assistance.
Symptom: No Association to Cisco Aironet Access Points
After the Greeting Message displays, if a phone continues to cycle through messages displaying on the phone screen, the phone is not associating with the access point properly. The phone cannot successfully start up unless it associates and authenticates with an access point.
Verifying Access Point Settings
The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G must first authenticate and associate with an access point before it can obtain an IP address. The phone follows this start up process with the access point:
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Check the SSID settings on the access point and on the phone to be sure the SSID matches.
Check the authentication type settings on the access point and on the phone to be sure authentication and encryption settings match.
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If using static WEP, check the WEP key on the phone to be sure it matches the WEP key on the access point. Reenter the WEP key on the phone to be sure it is correct.
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Error Messages During Authentication
If you see the following error messages, check these problems:
Authentication failed, No AP found
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EAP authentication failed
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AP Error—Cannot support all requested capabilities
On the access point, check that CKIP/CMIC is not enabled for the voice VLAN SSID. The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G does not support these features.
Symptom: No Registration to Cisco Unified Communications Manager
If a phone proceeds past the first stage (authenticating with access point) and continues to cycle through the messages displaying on the phone screen, the phone is not starting up properly. The phone cannot successfully start up until it connects to the LAN and registers with a Cisco Unified Communications Manager server.
These sections can assist you in determining the reason that the phone is unable to start up properly:
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Registering the Phone with Cisco Unified Communications Manager
A Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G can register with a Cisco Unified Communications Manager server only if the phone has been added to the server or if auto-registration is enabled. If you see the error message, "Registration Rejected," review the information and procedures in the "Adding Users to Cisco Unified Communications Manager" section on page 7-21 to ensure that the phone has been added to the Cisco Unified Communications Manager database.
To verify that the phone is in the Cisco Unified Communications Manager database, choose Device > Phone > Find from Cisco Unified Communications Manager Administration to search for the phone based on its MAC Address. To determine the MAC address of a phone, see "Viewing Device Information" section on page 8-4.
If the phone is already entered in the Cisco Unified Communications Manager database, its configuration file may be damaged. See "Creating a New Configuration File" section for assistance.
Checking Network Connectivity
If the network is down between the access point and the TFTP server or Cisco Unified Communications Manager, the phone cannot start up properly. Ensure that IP connectivity exists between the WLAN and the Cisco Unified Communications Manager and TFTP servers.
Verifying TFTP Server Settings
The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G uses the TFTP server setting to identify the primary TFTP server to use. If the TFTP server does not respond to the request, then the Communications Manager1 (CM1) shows as TFTP_AS_CM if the phone has not registered with Cisco Unified Communications Manager before.
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The phone tries to create a TCP connection to the TFTP IP address and then to the gateway. If Cisco Unified Communications Manager service is not running on the TFTP server, or if SRST is not running on the gateway, the wireless IP phone may continually cycle while attempting to contact the identified TFTP server.
The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G does not cache the IP information passed from the DHCP server, so the TFTP request must be sent and responded to every time the phone power cycles.
If you have assigned a static IP address to the phone, you must manually enter this setting. See "Configuring IP Network Settings" section on page 4-23.
If you are using DHCP, the phone obtains the address for the TFTP server from the DHCP server. Check the IP address configured in the DHCP server.
You can also enable the phone to use a static TFTP server. Such a setting is particularly useful if the phone was recently moved from one location to another.
For information about determining and changing TFTP server settings, see "Configuring IP Network Settings" section on page 4-23 or "Viewing the Current Configuration" section on page 8-11.
Verifying IP Addresses
You should verify the IP addressing for the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G. If you are using DHCP, the DHCP server should provide these values. If you have assigned a static IP address to the phone, you must enter these values manually.
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Check for these problems:
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If you are using DHCP, check the IP addresses distributed by your DHCP server. Be aware of DHCP conflicts and duplicate IP addresses. See Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks, available at this URL: http://www.cisco.com/warp/customer/473/100.html#41
For information about determining and changing IP addressing, see "Configuring IP Network Settings" section on page 4-23
Verifying DNS Settings
If you are using DNS to refer to Cisco Unified Communications Manager, you must ensure that you have specified a DNS server. You should also verify that there is a CNAME entry in the DNS server for the Cisco Unified Communications Manager system.
You must also ensure that DNS is configured to do reverse look-ups. The default setting on Windows 2000 is to perform forward-only look-ups.
For information about determining and changing DNS settings, see "Configuring IP Network Settings" section on page 4-23.
Verifying Cisco Unified Communications Manager and TFTP Service Status
The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G attempts to open a TCP connection to all the Cisco Unified Communications Manager servers that are part of the assigned Cisco Unified Communications Manager group.
If the Cisco Unified Communications Manager or TFTP services are not running, phones might not be able to start up properly. However, in such situations, it is likely that you are experiencing a system-wide failure and that other phones and devices are unable to start up properly.
If the Cisco Unified Communications Manager service is not running, all devices on the network that rely on it to make phone calls will be affected. If the TFTP service is not running, many devices will not be able to start up successfully.
For more information, see the Cisco Unified Communications Manager Administration Guide and the Cisco Unified Serviceability Administration Guide.
Creating a New Configuration File
If you continue to have problems with a particular phone that other suggestions in this chapter do not resolve, the configuration file might be corrupted.
To create a new configuration file, follow these steps:
Procedure
Step 1
Step 2
Step 3
Step 4
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Related Topics
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Resolving Voice Quality and Roaming
Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G users might have problems with voice quality and connectivity when roaming with their phones. See the following sections for troubleshooting information:
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Symptom: Cisco Unified Wireless IP Phone Resets Unexpectedly
If users report that their phones are resetting during calls or resetting while idle on their desk, you should investigate the cause. If the network connection and Cisco Unified Communications Manager connection are stable, a Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G should not reset on its own.
Typically, a phone resets if it has problems connecting to the access point and LAN or to Cisco Unified Communications Manager. These sections can help you identify the cause of a phone resetting in your network:
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Verifying Access Point Settings
Verify that the wireless configuration is correct. For example, check if the particular access point or switch to which the phone is connected is down. See "Site Survey Verification" section on page 2-20 for information about access point settings.
Identifying Intermittent Network Outages
Intermittent network outages affect data and voice traffic differently. Your network may be experiencing intermittent outages without detection. If so, data traffic can resend lost packets and verify that packets are received and transmitted. However, voice traffic cannot recapture lost packets. The phone can retransmit and attempt to recover, or if the phone reaches the maximum retransmit rate, it drops the packets or loses association with the access point.
If you are experiencing problems with the voice network, you should investigate whether an existing problem is simply being exposed.
Verifying DHCP Settings
To determine if the phone has been properly configured to use DHCP, follow these steps:
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Cisco Unified IP Phones send messages with request type 151 to renew their DHCP address leases. If the DHCP server expects messages with request type 150, the lease will be denied, forcing the phone to restart and request a new IP address from the DHCP server.
Verifying Voice VLAN Configuration
If the Cisco Unified IP Phone appears to reset during heavy network usage (for example, following extensive web surfing on a computer connected to same access point and switch as phone), it is likely that you do not have a voice VLAN or the appropriate QoS settings configured.
By isolating the wireless phones on a separate auxiliary VLAN, you can use QoS to prioritize the voice traffic over data traffic and improve the voice quality. See "Voice QoS in a Wireless Network" section on page 2-11 for details.
Verifying that the Phones Have Not Been Intentionally Reset
If you are not the only administrator with access to Cisco Unified Communications Manager, you should verify that no one else has intentionally reset the phones.
Eliminating DNS or Other Connectivity Errors
If the phone does not register with Cisco Unified Communications Manager, check to see if you are using host names or IP addresses for Cisco Unified Communications Manager servers.
To eliminate DNS or other connectivity errors, follow these steps:
Procedure
Step 1
Step 2
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To determine the MAC address of a phone, see "Viewing Device Information" section on page 8-4.
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Symptom: Audio Problems
When users report that active phone calls have poor voice quality that includes choppy audio, static or gaps in audio, or no audio, you can use the following suggestions to identify the cause of the problem.
These sections can assist you with the following symptoms:
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One-Way Audio During a Connected Call
Use the following list to identify possible causes for the problem:
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Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G firmware supports dynamic transmit power control (DTPC). The phone uses the transmit power that the access point advertises upon association.
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See "Site Survey Verification" section on page 2-20 for more information.
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Symptom: Improper Roaming and Voice Quality or Lost Connection
If users report that when engaged in an active phone call and walking from one location to another (roaming), the voice quality deteriorates or the connection is lost, you can use the following suggestions to identify the cause of the problem.
These sections can assist you with the following symptoms:
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Voice Quality Deteriorates While Roaming
Check the RSSI on the destination access point to see if the signal strength is adequate. The next access point should have an RSSI value of -67 dBm or greater.
Check the site survey to determine if the channel overlap is adequate for the phone and the access point to hand off the call to the next access point before the signal is lost from the previous access point.
Check to see if noise or interference in the coverage area is too great.
Check that signal to noise ratio (SNR) levels are 25 db or higher for acceptable voice quality.
Delays in Voice Conversation While Roaming
Use the Site Survey Utility on the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G to see if there is another acceptable access point as a roaming option. The next access point should have an signal of -67 dBm to roam successfully.
Check the Cisco Catalyst 45xx switch to see if it has the correct version of Supervisor (SUP) blades. The blades must be versions SUP2+ or higher to prevent roaming delays.
Phone Loses Connection with Cisco Unified Communications Manager While Roaming
Check for the following configuration or connectivity issues between the phone and the access point:
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Phone Does Not Roam Back to Preferred Band
For troubleshooting information, see the Cisco Unified Wireless IP Phone 7925 and 7926 Series Deployment Guide.
Monitoring the Voice Quality of Calls
To measure the voice quality of calls that are sent and received within the network, Cisco Unified IP Phones use these statistical metrics that are based on concealment events. The DSP plays concealment frames to mask frame loss in the voice packet stream.
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MOS LQK scores are produced by a Cisco proprietary algorithm, Cisco Voice Transmission Quality (CVTQ) index. Depending on the MOS LQK version number, these scores might be compliant with the International Telecommunications Union (ITU) standard P.564. This standard defines evaluation methods and performance accuracy targets that predict listening quality scores based on observation of actual network impairment.
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Listening quality scores (MOS LQK) relate to the clarity or sound of the received voice signal. Conversational quality scores (MOS CQ such as G.107) include impairment factors, such as delay, that degrade the natural flow of conversation.
For information about configuring voice quality metrics for phones, see the "Phone Features" section in the "Cisco Unified IP Phone" chapter in Cisco Unified Communications Manager System Guide.
You can access voice quality metrics remotely by using Streaming Statistics (see Chapter 9, "Monitoring the Cisco Unified Wireless IP Phone Remotely."
Using Voice Quality Metrics
To use the metrics for monitoring voice quality, note the typical scores under normal conditions of zero packet loss, and use the metrics as a baseline for comparison.
It is important to distinguish significant changes from random changes in metrics. Significant changes are scores that change about 0.2 MOS or greater and persist in calls that last longer than 30 seconds. Conceal Ratio changes should indicate greater than 3 percent frame loss.
MOS LQK scores can vary based on the codec that the Cisco Unified IP Phone uses. The following codecs provide these MOS LQK scores under normal conditions with zero frame loss:
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A Conceal Ratio of zero indicates that the IP network is delivering frames and packets on time with no loss.
Troubleshooting Tips
When you observe significant and persistent changes to metrics, use Table 10-1 for general troubleshooting information.
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General Troubleshooting Information
The following topics provide general information and tips for troubleshooting the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G.
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Common Phone Status Messages
Table 10-2 provides a list of common status messages that display on the phone screen. The table provides possible causes and recommended actions to assist with troubleshooting the problem.
Table 10-2 Common Phone Status Messages
Network Busy
The phone is unable to complete a call.
The WLAN is not able to allocate bandwidth for the phone to complete the call.
Wait a few minutes and try the call again. If the problem persists, the WLAN might be congested. Consider increasing the WLAN bandwidth.
Leaving Service Area
The phone is unable to place or receive calls. The no signal icon displays on the phone screen.
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The phone is out of range of all APs. Move to a location that is within the coverage area.
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Locating Network Services
The phone is searching for an AP.
The phone is searching all beacons and scanning for a channel and SSID to use.
Wait for the phone to complete the searching and scanning process. Depending on the signal strength of the available WLAN, this process can take a few minutes.
Authentication Failed
The phone is unable to access the WLAN, and the main phone screen is not active.
The authentication server does not accept the security credentials.
Verify that the security mode and credentials are correct by viewing the Network profile. For information about accessing and changing Network profiles, see "Accessing a Network Profile" section on page 5-2.
Configuring IP
The main phone screen is not active.
The phone is attempting to obtain network parameters such as its IP address, or the IP address of the gateway or router from the DHCP server.
Wait a few minutes for the phone to obtain the network parameters.
If the phone unable to retrieve the IP address, then check that the DHCP server is up and running.
Configuring CM List
The main phone screen is not active.
The phone is downloading its configuration files from the TFTP server.
Wait a few minutes for the phone to download all of its configuration files.
Troubleshooting Tips for the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G
Table 10-3 provides general troubleshooting information for the wireless IP phone.
Table 10-3 Cisco Unified Wireless IP Phone Troubleshooting Tips
Phone is resetting
The phone resets when it loses contact with the Cisco Unified Communications Manager software. This lost connection can be due to any network connectivity disruption, including access point problems, switch outages, and switch reboots.
See "Symptom: Cisco Unified Wireless IP Phone Resets Unexpectedly" section.
Time on phone is incorrect
Sometimes the time or date on the phone is incorrect. The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G gets its time and date when it registers with Cisco Unified Communications Manager. Power cycle the phone to reset the time or date.
The time shows in either 12 hour or 24 hour format.
Ring volume is too low
To see if the ring volume is set correctly on the phone, choose Settings >Phone Settings > Sound Settings > Volumes. Scroll up for the highest volume
You can also press the volume button on the side of the phone and the volume setting appears on the phone screen.
Phone does not ring
To see if the phone is set to ring, choose Settings > Phone Settings > Sound Settings > Alert Pattern, and check that it a ring setting is selected.
To see if a ring tone has been set for the phone, choose Settings > Phone Settings > Ring Tone. If none is set, add a ring tone for the phone.
To see if the speaker is functioning properly, adjust the ring volume settings to the highest level. Enable keypad tones or call the phone to check the speaker.
One-way audio on phone
Check that the speaker is functioning properly. Adjust the speaker volume setting and call the phone to check the speaker.
Check that ARP caching has been set on the AP. See "Site Survey Verification" section on page 2-20.
Delays when roaming from one location to another
If Cisco Catalyst 45xx series switches are being used as the main Layer 3 switches in the network, ensure that the supervisor blades are a minimum SUP2+ or later version. The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G (or any wireless client) experiences roaming delays when an earlier version (SUP 1 or SUP2) blade is used.
Phone firmware downgrades
After applying a Cisco Unified Communications Manager upgrade or patch, that is older than the current Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G firmware, the phones could automatically downgrade to the load contained in the patch. Check the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G device default image in the TFTP folder to fix this problem.
Battery life is shorter than specified
An unstable RF environment can cause the phone to remain in active mode because it is constantly seeking an AP. This reduces the battery life considerably. When leaving an area of coverage, shut down the phone.
Higher phone transmit power can affect battery life.
To maximize idle time on the phone and conserve battery life, you need to optimize the registration time so the phone can go into power save mode more often.
Phone call cannot be established
The phone does not have a DHCP IP address, is unable to register to Cisco Unified Communications Manager, and shows a Configuring IP or Registering message.
Verify the following:
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Call established with the iLBC protocol does not show that the iLBC codec is being used
Call statistics display does not show iLBC as the receiver/sender codec.
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Related Topics
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Logging Information for Troubleshooting
The following options can help you gather troubleshooting information:
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Using a System Log Server
To gather information about problems with the wired network that can cause roaming delays or no connectivity, set up a system log server. Enable "syslog" on the network switches and access points that is logged to the system log server. Also enable Network Time Protocol (NTP) so that all access points and switches use the same times.
For information about setting up a system log server, see "Configuring Trace Settings" section on page 4-27.
Using the Trace Logs on the Unified IP Phone
When you are experiencing problems registering with Cisco Unified Communications Manager, or call connections, you can use the Trace Logs function to trace the path of a packet from the phone to Cisco Unified Communications Manager. The result shows the number of hops and the IP address of each hop to reach the Cisco Unified Communications Manager server. You can use this information to check connectivity between the phone, Cisco Unified Communications Manager servers and gateways during a call.
To download trace logs, click Download Logs from the Trace Logs page.
For information, see "Viewing Trace Logs" section on page 4-35.
Internet Explorer Error When Downloading Trace Logs
Depending on your settings, Internet Explorer might display an error when you download a trace log from the Trace Logs page.
To prevent this error from displaying, follow these steps:
Procedure
Step 1
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Step 4
Related Topics
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Erasing the Local Configuration
You can clear all locally stored configuration options in a phone from the Phone Settings menu. When you use the restore to factory default option, all user-defined entries in Network Profiles, Phone Settings, and Call History are erased.
To erase the local configuration, follow these steps:
Procedure
Step 1
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The phone briefly displays "Start factory reset now?"
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Or press No to cancel the reset.
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Caution
Related Topics
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