Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified Communications Manager 9.0 (SCCP and SIP)
Troubleshooting and Maintenance
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Troubleshooting and Maintenance

Contents

Troubleshooting and Maintenance

Troubleshooting and Maintenance Overview

This chapter provides information that can assist you in troubleshooting problems with your Cisco Unified IP Phone 7906G or 7911G or with your Cisco Unified Communications network. It also explains how to clean and maintain your phone.

For additional troubleshooting information, see the Using the 79xx Status Information For Troubleshooting tech note, available to registered Cisco.com users at this URL:

http:/​/​www.cisco.com/​en/​US/​products/​hw/​phones/​ps379/​products_​tech_​note09186a00800945bd.shtml

Troubleshooting

This section contains the following topics:

Startup Problems

After installing a Cisco Unified IP Phone into your network and adding it to Cisco Unified Communications Manager, the phone should start up as described in the Phone Startup Verification. If the phone does not start up properly, see the following sections for troubleshooting information:

Cisco Unified IP Phone Does Not Go Through Normal Startup Process

Problem

When you connect a Cisco Unified IP Phone into the network port, the phone should go through its normal startup process and the LCD screen should display information.

Cause

If the phone does not go through the startup process, the cause may be faulty cables, bad connections, network outages, lack of power, and so on. Or, the phone may not be functional.

Solution

To determine whether the phone is functional, follow these suggestions to systematically eliminate these other potential problems:

  1. Verify that the network port is functional:
    • Exchange the Ethernet cables with cables that you know are functional.
    • Disconnect a functioning Cisco Unified IP Phone from another port and connect it to this network port to verify the port is active.
    • Connect the Cisco Unified IP Phone that will not start up to a different network port that is known to be good.
    • Connect the Cisco Unified IP Phone that will not start up directly to the port on the switch, eliminating the patch panel connection in the office.
  2. Verify that the phone is receiving power:
    • If you are using external power, verify that the electrical outlet is functional.
    • If you are using in-line power, use the external power supply instead.
    • If you are using the external power supply, switch with a unit that you know to be functional.
  3. If the phone still does not start up properly, power up the phone with the handset off-hook. When the phone is powered up in this way, it attempts to launch a backup software image.
  4. If the phone still does not start up properly, perform a factory reset of the phone. For instructions, see Perform Factory Reset.

If after attempting these solutions, the LCD screen on the Cisco Unified IP Phone does not display any characters after at least five minutes, contact a Cisco technical support representative for additional assistance.

Cisco Unified IP Phone Does Not Register with Cisco Unified Communications Manager

If the phone proceeds past the first stage of the startup process (LED buttons flashing on and off) but continues to cycle through the messages displaying on the LCD screen, the phone is not starting up properly. The phone cannot successfully start up unless it is connected to the Ethernet network and it has registered with a Cisco Unified Communications Manager server.

These sections can assist you in determining the reason the phone is unable to start up properly:

Phone Displays Error Messages
Problem

Status messages display errors during startup.

Solution

As the phone cycles through the startup process, you can access status messages that might provide you with information about the cause of a problem. See Status Messages Screen for instructions about accessing status messages and for a list of potential errors, their explanations, and their solutions.

Cisco Unified Communications Manager Phone Registration
Problem

The phone is not registered with the Cisco Unified Communications Manager

Solution

A Cisco Unified IP Phone can register with a Cisco Unified Communications Manager server only if the phone has been added to the server or if autoregistration is enabled. Review the information and procedures in the Cisco Unified Communications Manager Phone Addition Methods 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 > Find from Cisco Unified Communications Manager Administration to search for the phone based on its MAC Address. For information about determining a MAC address, see Cisco Unified IP Phone MAC Address Determination.

If the phone is already in the Cisco Unified Communications Manager database, its configuration file may be damaged. See Create New Configuration File for assistance.

Phone Cannot Connect to TFTP Server or to Cisco Unified Communications Manager
Problem

If the network is down between the phone and either the TFTP server or Cisco Unified Communications Manager, the phone cannot start up properly.

Solution

Ensure that the network is currently running.

TFTP Server Settings
Problem

The TFTP server settings may not be correct.

Solution

Check the TFTP settings. See Check TFTP Settings.

IP Address and Routing
Problem

The IP addressing and routing fields may not be correctly configured.

Solution

You should verify the IP addressing and routing settings on the phone. 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. See Check DHCP settings.

DNS Settings
Problem

The DNS settings may be incorrect.

Solution

If you are using DNS to refer to the TFTP server or to Cisco Unified Communications Manager, you must ensure that you have specified a DNS server. See Verify DNS Settings.

Cisco Unified Communications Manager Settings on Phone
Problem

The phone may not have the correct information about the Cisco Unified Communications Manager.

Solution

On the Cisco Unified IP Phone, press the Applications Menu button and select Settings > Network Configuration > Communications Manager 1–5. The Cisco Unified IP Phone 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 none of these options contain IP addresses or show Active or Standby, the phone is not properly registered with Cisco Unified Communications Manager. See Cisco Unified Communications Manager Phone Registration for tips on resolving this problem.

Cisco CallManager and TFTP Services Are Not Running
Problem

If the Cisco CallManager or TFTP services are not running, phones may not be able to start up properly. In such a situation, it is likely that you are experiencing a systemwide failure, and other phones and devices are unable to start up properly.

Solution

If the Cisco CallManager service is not running, all devices on the network that rely on it to make phone calls are affected. If the TFTP service is not running, many devices cannot start up successfully. For more information, see Start Service.

Configuration File Corruption
Problem

If you continue to have problems with a particular phone that other suggestions in this chapter do not resolve, the configuration file may be corrupted.

Solution

Create a new phone configuration file. See Create New Configuration File

Cisco Unified Communications Manager Phone Registration
Problem

The phone is not registered with the Cisco Unified Communications Manager.

Solution

A Cisco Unified IP Phone can register with a Cisco Unified Communications Manager server only if the phone has been added to the server or if autoregistration is enabled. Review the information and procedures in the Cisco Unified Communications Manager Phone Addition Methods 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. For information about determining a MAC address, see Cisco Unified IP Phone MAC Address Determination.

If the phone is already in the Cisco Unified Communications Manager database, its configuration file may be damaged. See Create New Configuration File for assistance.

Cisco Unified IP Phone Displays Security Error Message

Problem

The phone displays Security Error on the screen.

Cause

When a Cisco Unified IP Phone boots, it performs an internal Power On Self Test (POST). POST checks for some encryption functionality to be existing. If POST detects that encryption functionality is missing, the phone fails to boot, and the message Security Error appears on the screen.

Solution

To correct the problem, try the following steps:

  1. Reset the phone manually.
  2. If the phone does not start up properly, power up the phone with the handset off-hook. When the phone is powered up in this way, it attempts to launch a backup software image.
  3. If the phone still does not start up properly, perform a factory reset of the phone. For instructions, see Perform Factory Reset.

Cisco Unified IP Phone Resets Unexpectedly

If users report that their phones are resetting during calls or 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 IP Phone should not reset on its own.

Typically, a phone resets if it has problems connecting to the Ethernet network or to Cisco Unified Communications Manager. These sections can help you identify the cause of a phone resetting in your network:

Physical Connection Problems

Problem

The physical connection to the LAN may be broken.

Solution

Verify that the Ethernet connection to which the Cisco Unified IP Phone connects is up. For example, check whether the particular port or switch to which the phone connects is down and that the switch is not rebooting. Also ensure that no cable breaks exist.

Intermittent Network Outages

Problem

Your network may be experiencing intermittent outages.

Solution

Intermittent network outages affect data and voice traffic differently. Your network might 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. Rather than retransmitting a lost network connection, the phone resets and attempts to reconnect to the network. Contact the system administrator for information on known problems in the voice network.

DHCP Setting Errors

Problem

The DHCP settings may be incorrect.

Solution

The following suggestions can help you determine if the phone has been properly configured to use DHCP:

  1. Verify that you have properly configured the phone to use DHCP. See Network Configuration Menu for more information.
  2. Verify that the DHCP server has been set up properly.
  3. Verify the DHCP lease duration. Cisco recommends that you set the lease duration to 8 days. 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 renewal is denied, forcing the phone to restart and request a new IP address from the DHCP server.

Static IP Address Setting Errors

Problem

The static IP address assigned to the phone may be incorrect.

Solution

If the phone has been assigned a static IP address, verify that you have entered the correct settings.

Voice VLAN Setup Errors

Problem

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 switch as phone), it is likely that you do not have a voice VLAN configured.

Solution

Isolating the phones on a separate auxiliary VLAN increases the quality of the voice traffic.

Phones Have Not Been Intentionally Reset

Problem

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.

Solution

You can check whether a Cisco Unified IP Phone received a command from Cisco Unified Communications Manager to reset by pressing the Applications Menu button on the phone and choosing Settings > Status > Network Statistics. If the phone was recently reset one of these messages appears:

  • Reset-Reset: Phone received a Reset-Reset request from Cisco Unified Communications Manager Administration.
  • Reset-Restart: Phone received a Reset-Restart request from Cisco Unified Communications Manager Administration.

DNS or Other Connectivity Errors

Problem

The phone reset continues and you suspect DNS or other connectivity issues.

Solution

If the phone continues to reset, eliminate DNS or other connectivity errors with Determine DNS or Connectivity Issues.

Power Connection Problems

Problem

The phone does not appear to be powered up.

Solution

In most cases, a phone restarts if it powers up by using external power but loses that connection and switches to PoE. Similarly, a phone may restart if it powers up by using PoE and then connects to an external power supply.

Cisco Unified IP Phone Security Problems

The following sections provide troubleshooting information for the security features on the Cisco Unified IP Phone. For information about the solutions for any of these issues, and for additional troubleshooting information about security, see Cisco Unified Communications Manager Security Guide.

CTL File Problems

The following sections describe problems with the CTL file:

Authentication Error, Phone Cannot Authenticate CTL File
Problem

A device authentication error occurs.

Cause

CTL file does not have a Cisco Unified Communications Manager certificate or has an incorrect certificate.

Solution

Install a correct certificate.

CTL File Authenticates but Other Configuration Files Do Not Authenticate
Problem

Phone cannot authenticate any configuration files other than the CTL file.

Cause

A bad TFTP record exists, or the configuration file may not be signed by the corresponding certificate in the phone Trust List.

Solution

Check the TFTP record and the certificate in the Trust List.

ITL File Authenticates but Other Configuration Files Do Not Authenticate
Problem

Phone cannot authenticate any configuration files other than the ITL file.

Cause

The configuration file may not be signed by the corresponding certificate in the phone Trust List.

Solution

Re-sign the configuration file by using the correct certificate.

Phone Does Not Register
Problem

Phone does not register with Cisco Unified Communications Manager.

Cause

The CTL file does not contain the correct information for the Cisco Unified Communications Manager server.

Solution

Change the Cisco Unified Communications Manager server information in the CTL file.

Signed Configuration Files Are Not Requested
Problem

Phone does not request signed configuration files.

Cause

The CTL file does not contain any TFTP entries with certificates.

Solution

Configure TFTP entries with certificates in the CTL file.

802.1X Authentication Problems

802.1X authentication problems can be broken into the categories described in the following table.

Table 1 Identifying 802.1X Authentication Problems

If all the following conditions apply,

See

  • Phone cannot obtain a DHCP-assigned IP address.
  • Phone does not register with Cisco Unified Communications Manager.
  • 802.1X Authentication Status displays as "Held" (see 802.1X Authentication and Status).
  • Status menu displays 802.1X status as "Failed" (see Status Menu)

802.1X Enabled on Phone but Phone Does Not Authenticate

  • Phone cannot obtain a DHCP-assigned IP address.
  • Phone does not register with Cisco Unified Communications Manager.
  • Phone status display as "Configuring IP" or "Registering".
  • 802.1X Authentication Status displays as "Disabled".
  • Status menu displays DHCP status as timing out.

802.1X Not Enabled

  • Phone cannot obtain a DHCP-assigned IP address.
  • Phone does not register with Cisco Unified Communications Manager.
  • Phone status display as "Configuring IP" or "Registering."
  • Cannot access phone menus to verify 802.1X status.

Factory Reset of Phone Has Deleted 802.1X Shared Secret

802.1X Enabled on Phone but Phone Does Not Authenticate
Problem

The phone cannot authenticate.

Cause

These errors typically indicate that 802.1X authentication is enabled on the phone, but the phone is unable to authenticate.

Solution
  1. Verify that you have properly configured the required components (see 802.1X Authentication for more information).
  2. Confirm that the shared secret is configured on the phone. See 802.1X Authentication and Status for more information).
    • If the shared secret is configured, verify that you have the same shared secret entered on the authentication server.
    • If the shared secret is not configured, enter it, and ensure that it matches the shared secret on the authentication server.
802.1X Not Enabled
Problem

The phone does not have 802.1X configured.

Cause

These errors typically indicate that 802.1X is not enabled on the phone.

Solution

To enable 802.1X, see Security Configuration Menu.

Factory Reset of Phone Has Deleted 802.1X Shared Secret
Problem

After a reset, the phone does not authenticate.

Cause

These errors typically indicate that the phone completed a factory reset (see Perform Factory Reset) while 802.1X was enabled. A factory reset deletes the shared secret, which is required for 802.1X authentication and network access.

Solution

To resolve this issue, you have two options:

  • Temporarily disable 802.1X on the switch
  • Temporarily move the phone to a network environment that is not using 802.1X authentication

After the phone starts up normally in one of these conditions, you can access the 802.1X configuration menus and re-enter the shared secret (see 802.1X Authentication and Status).

Audio and Video Problems

The following sections describe how to resolve audio and video problems,

Phone Display Is Wavy

Problem

The display appears to have rolling lines or a wavy pattern.

Cause

The phone might be interacting with certain types of older fluorescent lights in the building.

Solution

Move the phone away from the lights or replace the lights to resolve the problem.

Poor Audio Quality With Calls That Route Outside Cisco Unified Communications Manager

Problem

Poor quality with tandem audio encoding. Tandem encoding can occur when making calls between an IP Phone and a digital cellular phone, when using a conference bridge, or in situations where IP to IP calls are partially routed across the PSTN.

Cause

In Cisco Unified Communications Manager, you can configure the network to use the G.729 protocol (the default is G.711). When using G.729, calls between an IP phone and a digital cellular phone will have poor voice quality.

Solution

Use the G.729 codec only when absolutely necessary.

No Speech Path

Problem

One or more people on a call do not hear any audio.

Solution

When at least one person in a call does not receive audio, IP connectivity between phones is not established. Check the configuration of routers and switches to ensure that IP connectivity is properly configured.

General Telephone Call Problems

The following sections help troubleshoot general telephone call problems.

Phone Call Cannot Be Established

Problem

A user complains about not being able to make a call.

Cause

The phone does not have a DHCP IP address, is unable to register to Cisco Unified Communications Manager. Phones with an LCD display show the message Configuring IP or Registering. Phones without an LCD display play the reorder tone (instead of dial tone) in the handset when the user attempts to make a call.

Solution
  1. Verify the following:
    1. The Ethernet cable is attached.
    2. The Cisco CallManager service is running on the Cisco Unified Communications Manager server.
    3. Both phones are registered to the same Cisco Unified Communications Manager.
  2. Audio server debug and capture logs are enabled for both phones. If needed, enable Java debug.

Phone Does Not Recognize DTMF Digits or Digits Are Delayed

Problem

The user complains that numbers are missed or delayed when the keypad is used.

Cause

Pressing the keys too quickly can result in missed or delayed digits.

Solution

Keys should not be pressed rapidly.

Troubleshooting Procedures

These procedures can be used to identify and correct problems.

Check TFTP Settings

Procedure
    Step 1   You can determine the IP address of the TFTP server used by the phone by pressing the Settings button on the phone, choosing IPv4 > Network Configuration, and scrolling to the TFTP Server 1 option.
    Step 2   If you have assigned a static IP address to the phone, you must manually enter a setting for the TFTP Server 1 option. See Network Configuration Menu.
    Step 3   If you are using DHCP, the phone obtains the address for the TFTP server from the DHCP server. Check the IP address configured in Option 150.
    Step 4   You can also enable the phone to use an alternate TFTP server. Such a setting is particularly useful if the phone was recently moved from one location to another. See Network Configuration Menu for instructions.

    Check DHCP settings

    Procedure
      Step 1   On the Cisco Unified IP Phone, press Applications Menu, then select Settings > Network Configuration, and look at the following options:
      1. DHCP Server: If you have assigned a static IP address to the phone, you do not need to enter a value for the DHCP Server option. However, if you are using a DHCP server, this option must have a value. If it does not, check your IP routing and VLAN configuration. For more information, see Troubleshooting Switch Port Problems, available at this URL: http:/​/​www.cisco.com/​en/​US/​customer/​products/​hw/​switches/​ps708/​prod_​tech_​notes_​list.html
      2. IP Address, Subnet Mask, Default Router: If you have assigned a static IP address to the phone, you must manually enter settings for these options. See Network Configuration Menu for instructions.
      Step 2   If you are using DHCP, check the IP addresses distributed by your DHCP server. For more information, see Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks, available at this URL: http:/​/​www.cisco.com/​en/​US/​tech/​tk648/​tk361/​technologies_​tech_​note09186a00800f0804.shtml

      Verify DNS Settings

      To verify DNS settings, perform these steps:

      Procedure
        Step 1   Press Applications Menu.
        Step 2   Select Settings > Network Configuration > DNS Server 1.
        Step 3   You should also verify that there is a CNAME entry in the DNS server for the TFTP server and for the Cisco Unified Communications Manager system.
        Step 4   You must also ensure that DNS is configured to do reverse look-ups. Windows 2000 is configured by default only to perform forward look-ups.

        Start Service


        Note


        A service must be activated before it can be started or stopped. To activate a service, choose Tools > Service Activation.


        To start a service, follow these steps:

        Procedure
          Step 1   From Cisco Unified Communications Manager Administration, choose Cisco Unified Serviceability from the Navigation drop-down list and click Go.
          Step 2   Choose Tools > Control Center - Feature Services.
          Step 3   Choose the primary Cisco Unified Communications Manager server from the Server drop-down list.

          The window displays the service names for the server that you chose, the status of the services, and a service control panel to start or stop a service.

          Step 4   If a service has stopped, click the corresponding radio button and then click Start.

          The Service Status symbol changes from a square to an arrow.


          Create New Configuration File


          Note


          • When you remove a phone from the Cisco Unified Communications Manager database, its configuration file is deleted from the Cisco Unified Communications Manager TFTP server. The phone directory number or numbers remain in the Cisco Unified Communications Manager database. They are called "unassigned DNs" and can be used for other devices. If unassigned DNs are not used by other devices, delete them from the Cisco Unified Communications Manager database. You can use the Route Plan Report to view and delete unassigned reference numbers. For more information, see the Cisco Unified Communications Manager Administration Guide.
          • Changing the buttons on a phone button template, or assigning a different phone button template to a phone, may result in directory numbers that are no longer accessible from the phone. The directory numbers are still assigned to the phone in the Cisco Unified Communications Manager database, but there is no button on the phone with which calls can be answered. These directory numbers should be removed from the phone and deleted if necessary.

          To create a new configuration file, perform these steps:

          Procedure
            Step 1   From Cisco Unified Communications Manager, choose Device > Phone > Find to locate the phone experiencing problems.
            Step 2   Choose Delete to remove the phone from the Cisco Unified Communications Manager database.
            Step 3   Add the phone back to the Cisco Unified Communications Manager database. See Cisco Unified Communications Manager Phone Addition Methods for details.
            Step 4   Power cycle the phone.

            Determine DNS or Connectivity Issues

            If the phone continues to reset, follow these steps to eliminate DNS or other connectivity errors:

            Procedure
              Step 1   Use the Erase softkey to reset phone settings to their default values. See Cisco Unified IP Phone Reset or Restore for details.
              Step 2   Modify DHCP and IP settings.
              1. Disable DHCP. See Network Configuration Menu for instructions.
              2. Assign static IP values to the phone. See Network Configuration Menu for instructions. Use the same default router setting used for other functioning Cisco Unified IP Phones.
              3. Assign TFTP server. See Network Configuration Menu for instructions. Use the same TFTP server used for other functioning Cisco Unified IP Phones.
              Step 3   On the Cisco Unified Communications Manager server, verify that the local host files have the correct Cisco Unified Communications Manager server name mapped to the correct IP address. For more informmation, see Configuring The IP Hosts File on a Windows 2000 Communications Manager Server, available at this URL: http:/​/​www.cisco.com/​en/​US/​products/​sw/​voicesw/​ps556/​products_​tech_​note09186a0080094976.shtml
              Step 4   From Cisco Unified Communications Manager, choose System > Server and verify that the server is referred to by its IP address and not by its DNS name.
              Step 5   From Cisco Unified Communications Manager, choose Device > Phone and verify that you have assigned the correct MAC address to this Cisco Unified IP Phone. For information about determining a MAC address, see Cisco Unified IP Phone MAC Address Determination.
              Step 6   Power cycle the phone.

              General Troubleshooting Information

              This section provides troubleshooting information for some common issues that might occur on the Cisco Unified IP Phone.

              The following table provides general troubleshooting information for the Cisco Unified IP Phone.

              Table 2 Cisco Unified IP Phone Troubleshooting

              Summary

              Explanation

              Daisy-chaining IP phones.

              Cisco does not support connecting an IP phone to another IP phone through the PC port. Each IP phone should directly connect to a switch port. If phones are connected together in a line (daisy chaining by using the PC port), the phones will not work.

              Prolonged broadcast storms cause IP phones to re-register.

              Prolonged broadcast storms (lasting several minutes) on the voice VLAN cause the IP phones to reregister with another Cisco Unified Communications Manager server.

              Moving a network connection from the phone to a workstation.

              If you are powering your phone through the network connection, you must be careful if you decide to unplug the phone’s network connection and plug the cable into a desktop computer.

              Caution   

              The network card in the computer cannot receive power through the network connection; if power comes through the connection, the network card can be destroyed. To protect a network card, wait 10 seconds or longer after unplugging the cable from the phone before plugging it into a computer. This delay gives the switch enough time to recognize that there is no longer a phone on the line and to stop providing power to the cable.

              Changing the telephone configuration.

              By default, the network configuration options are locked to prevent users from making changes that could impact their network connectivity. You must unlock the network configuration options before you can configure them. See Unlock and Lock Options for details.

              Phone 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 cable breaks, switch outages, and switch reboots.

              Loopback condition.

              A loopback condition can occur when the following conditions are met:

              • The SW Port Configuration option in the Network Configuration menu on the phone is set to 10 Half (10-BaseT / half duplex)
              • The phone receives power from an external power supply.
              • The phone is powered down or the power supply is disconnected.

              In this case, the switch port on the phone can become disabled and the following message will appear in the switch console log:

              HALF_DUX_COLLISION_EXCEED_THRESHOLD

              To resolve this problem, reenable the port from the switch.

              Peer to peer image distribution fails.

              If the peer to peer image distribution fails, the phone will default to using the TFTP server to download firmware. Access the log messages stored on the remote logging machine to help debug the peer to peer image distribution feature.

              Note   

              These log messages are different than the log messages sent to the phone log.

              Cisco VT Advantage/Unified Video Advantage (CVTA)

              If you are having problems getting CVTA to work, make sure that the PC Port is enabled, and that CDP is enabled on the PC port. See Network Configuration Menu.

              (applies to Cisco Unified IP Phone 7911G only)

              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.

              1. Check the following using Cisco Unified Communications Manager Administration:
                • Both phones are in the iLBC device pool.
                • The iLBC device pool is configured with the iLBC region.
                • The iLBC region is configured with the iLBC codec.
              2. Capture a sniffer trace between the phone and Cisco Unified Communications Manager and verify that SCCP messages,OpenReceiveChannel, and StationMediaTransmit messages have media payload type value equal to 86. If so, the problem is with the phone; otherwise, the problem is with the Cisco Unified Communications Manager configuration.
              3. Enable audio server debug and capture logs from both phones. If needed, enable Java debug.

              Cisco Unified IP Phone Reset or Restore

              There are two methods for resetting or restoring the Cisco Unified IP Phone:

              Basic Reset

              Performing a basic reset of a Cisco Unified IP Phone provides a way to recover if the phone experiences an error and provides a way to reset or restore various configuration and security settings.

              The following table describes the ways to perform a basic reset. You can reset a phone with any of these operations any time after the phone has started up. Choose the operation that is appropriate for your situation.

              Table 3 Basic Reset Methods

              Operation

              Action

              Explanation

              Reset phone

              From any screen (but not when the phone is idle), press **#**.

              Resets any user and network configuration changes that you have made but that the phone has not written to its flash memory to previously saved settings, then restarts the phone.

              Erase softkey

              From the Settings menu, unlock phone options (see Unlock and Lock Options). Then press Erase.

              Resets user and network configuration settings to their default values, deletes the CTL file from the phone, and restarts the phone.

              From the Network Configuration menu, unlock phone options (see Unlock and Lock Options). Then press Erase.

              Resets network configuration settings to their default values and resets the phone. This method causes DHCP reconfigure the IP address of the phone.

              From the Security Configuration menu, unlock phone options (see Unlock and Lock Options). Then press Erase.

              Deletes the CTL file from the phone and restarts the phone.

              Perform Factory Reset

              When you perform a factory reset of the Cisco Unified IP Phone, the following information is erased or reset to its default value:

              • CTL file: Erased
              • User configuration settings: Reset to default values
              • Network configuration settings: Reset to default values
              • Call histories: Erased
              • Locale information: Reset to default values
              • Phone application: Erased. The phone recovers by loading the term11.default.loads file.

              Note


              This phone must be on a DHCP-enabled network before you can perform these steps.


              To perform a factory reset of a phone, perform these steps:

              Procedure
                Step 1   Plug in the power adapter to wake up the phone while sleeping.

                The phone begins its power-up cycle.

                Step 2   While the phone is powering up, and before the Applications Menu button flashes on and off, press and hold #. Continue to hold # until the message LED on the handset flashes on and off in sequence in red.
                Step 3   Release # and press 123456789*0#.

                You can press a key twice in a row, but if you press the keys out of sequence, the factory reset will not take place.

                After you press these keys, the message LED on the handset flashes faster in red, and the phone goes through the factory reset process.

                Do not power down the phone until it completes the factory reset process, and the main screen appears.


                Additional Troubleshooting Information

                If you have additional questions about troubleshooting the Cisco Unified IP Phones, these Cisco.com websites provide you with more tips.

                Maintenance

                This section includes these topics:

                Quality Report Tool

                The Quality Report Tool (QRT) is a voice quality and general problem-reporting tool for the Cisco Unified IP Phone. The QRT feature is installed as part of the Cisco Unified Communications Manager installation.

                You can configure Cisco Unified IP Phones with QRT. When you do so, users can report problems with phone calls pressing QRT. This softkey is available only when the Cisco Unified IP Phone is in the Connected, Connected Conference, Connected Transfer, or OnHook states.

                When a user presses QRT, a list of problem categories appears. The user selects the appropriate problem category, and this feedback is logged in an XML file. Actual information logged depends on the user selection, and if the destination device is a Cisco Unified IP Phone.

                For more information about using QRT, see the Cisco Unified Serviceability Administration Guide.

                Voice Quality Monitoring

                To measure the voice quality of calls that are sent and received within the network, Cisco Unified IP Phones use the following statistical metrics that are based on concealment events. The Digital Signal Processor (DSP) plays concealment frames to mask frame loss in the voice packet stream.

                • Concealment Ratio metrics: Shows the ratio of concealment frames over total speech frames. The phone calculates an interval conceal ratio every 3 seconds.
                • Concealed Second metrics: Shows the number of seconds in which the DSP plays concealment frames due to lost frames. A severely "concealed second" is a second in which the DSP plays more than five percent concealment frames.
                • MOS-LQK metrics: Uses a numeric score to estimate the relative voice listening quality. The Cisco Unified IP Phone calculates the mean opinion score (MOS) for listening quality (LQK) based audible concealment events due to frame loss in the preceding 8 seconds, and includes perceptual weighting factors such as codec type and frame size. The phone uses the Cisco proprietary algorithm, Cisco Voice Transmission Quality (CVTQ) index, to produce MOS LQK scores. 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.

                Note


                Concealment ratio and concealment seconds are primary measurements based on frame loss while MOS LQK scores project a "human-weighted" version of the same information on a scale from 5 (excellent) to 1 (bad) for measuring listening quality.


                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.

                You can access voice quality metrics from the Cisco Unified IP Phone by using the Call Statistics screen or remotely by using Streaming Statistics.

                Voice Quality Metric Interpretation

                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 maximum MOS LQK scores under normal conditions with zero frame loss:

                • G.711 codec gives 4.5 score
                • G.729A/ AB gives 3.8 score
                • G.728/iLBC gives 3.9 score
                • CVTQ does not support wideband (7 kHz) speech codecs, because ITU has not defined the extension of the technique to wideband. Therefore, MOS scores that correspond to G.711 performance are reported for G.722 calls to allow basic quality monitoring, rather than not reporting an MOS score.
                • Reporting G.711-scale MOS scores for wideband calls through the use of CVTQ allows basic quality classifications to be indicated as good/normal or bad/abnormal. Calls with high scores (approximately 4.5) indicate high quality/low packet loss, and lower scores (approximately 3.5) indicate low quality/high packet loss.
                • Unlike MOS, the Conceal Ratio and Concealed Seconds metrics remain valid and useful for both wideband and narrowband calls.

                A Conceal Ratio of zero indicates that the IP network is delivering frames and packets on time with no loss.

                Voice Quality Troubleshooting Tips

                When you observe significant and persistent changes to metrics, use the following table for general troubleshooting information:

                Table 4 Changes to Voice Quality Metrics

                Metric change

                Condition

                MOS LQK scores decrease significantly

                Network impairment from packet loss or high jitter:

                • Average MOS LQK decreases could indicate widespread and uniform impairment.
                • Individual MOS LQK decreases indicate bursty impairment.

                Cross-check with Conceal Ratio and Conceal Seconds for evidence of packet loss and jitter.

                MOS LQK scores decrease significantly

                Check to see whether the phone is using a different codec than expected (RxType and TxType).

                Check to see whether the MOS LQK version changed after a firmware upgrade.

                Conceal Ratio and Conceal Seconds increase significantly

                • Network impairment from packet loss or high jitter.

                Conceal Ratio is near or at zero, but the voice quality is poor.

                Noise or distortion in the audio channel such as echo or audio levels.

                Tandem calls that undergo multiple encode/decode, such as calls to a cellular network or calling card network.

                Acoustic problems coming from a speakerphone, handsfree cellular phone, or wireless headset.

                Check packet transmit (TxCnt) and packet receive (RxCnt) counters to verify that voice packets are flowing.


                Note


                Voice quality metrics do not account for noise or distortion, only frame loss.


                Cisco Unified IP Phone Cleaning

                To clean your Cisco Unified IP phone, use a soft, dry cloth to wipe the phone screen. Do not apply liquids or powders directly on the phone. As with all non-weather-proof electronics, liquids and powders can damage the components and cause failures.

                Disable the screen before cleaning it so that you will not inadvertently choose a feature from the pressure of the cleaning cloth. To disable the screen, press Display for more than one second. The phone displays Touchscreen Disabled or Phone Screen Disabled and the Display button flashes green.

                After one minute, the screen automatically reenables itself. To reenable the screen before that, press the flashing Display button for more than one second. The phone displays Touchscreen Enabled or Phone Screen Enabled.