Cisco Unified IP Phone 7931G Administration Guide for Cisco Unified Communications Manager 8.6 (SCCP and SIP)
Troubleshooting and Maintenance
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Troubleshooting and Maintenance

Table Of Contents

Troubleshooting and Maintenance

Resolving Startup Problems

Symptom: The Cisco Unified IP Phone Does Not Go Through its Normal Startup Process

Symptom: The Cisco Unified IP Phone Does Not Register with Cisco Unified CM

Identifying Error Messages

Checking Network Connectivity

Verifying TFTP Server Settings

Verifying IP Addressing and Routing

Verifying DNS Settings

Verifying Cisco Unified CM Settings

Cisco CallManager and TFTP Services Are Not Running

Creating a New Configuration File

Registering the Phone with Cisco Unified CM

Symptom: Cisco Unified IP Phone Unable to Obtain IP Address

Symptom: The Cisco Unified IP Phone Displays the Message Security Error

Cisco Unified IP Phone Resets Unexpectedly

Verifying Physical Connection

Identifying Intermittent Network Outages

Verifying DHCP Settings

Checking Static IP Address Settings

Verifying Voice VLAN Configuration

Verifying that the Phones Have Not Been Intentionally Reset

Eliminating DNS or Other Connectivity Errors

Checking Power Connection

Troubleshooting Cisco Unified IP Phone Security

General Troubleshooting Tips

Resetting or Restoring the Cisco Unified IP Phone

Performing a Basic Reset

Performing a Factory Reset

Using the Quality Report Tool

Monitoring the Voice Quality of Calls

Using Voice Quality Metrics

Troubleshooting Tips

Where to Go for More Troubleshooting Information

Cleaning the Cisco Unified IP Phone


Troubleshooting and Maintenance


This chapter provides information that can assist you in troubleshooting problems with your Cisco Unified Unified IP Phone 7931G or with your IP telephony 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. That document is available to registered Cisco.com users at this URL:

http://www.cisco.com/warp/customer/788/AVVID/telecaster_trouble.html

If you need additional assistance to resolve an issue, see the "Obtaining Documentation, Obtaining Support, and Security Guidelines" section.

This chapter includes these topics:

Resolving Startup Problems

Cisco Unified IP Phone Resets Unexpectedly

Troubleshooting Cisco Unified IP Phone Security

General Troubleshooting Tips

Resetting or Restoring the Cisco Unified IP Phone

Using the Quality Report Tool

Monitoring the Voice Quality of Calls

Where to Go for More Troubleshooting Information

Cleaning the Cisco Unified IP Phone

Resolving Startup Problems

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

Symptom: The Cisco Unified IP Phone Does Not Go Through its Normal Startup Process

Symptom: The Cisco Unified IP Phone Does Not Register with Cisco Unified CM

Symptom: Cisco Unified IP Phone Unable to Obtain IP Address

Symptom: The Cisco Unified IP Phone Does Not Go Through its Normal Startup Process

When you connect a Cisco Unified IP Phone into the network port, the phone should go through its normal startup process as described in Verifying the Phone Startup Process, and the phone screen should display information. 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.

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.

Switch the external power supply with a unit that you know to be functional.

If you are using a in-line power, make sure that the phone is connected to a switch that supports IEEE 802.3af Class 3. For more information, see Providing Power to the Phone.

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 Performing a Factory Reset.

If after attempting these solutions, the screen on the Cisco Unified IP Phone does not display any characters after at least 5minutes, contact a Cisco technical support representative for additional assistance.

Symptom: The Cisco Unified IP Phone Does Not Register with Cisco Unified CM

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 phone 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 CM server.

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

Identifying Error Messages

Checking Network Connectivity

Verifying TFTP Server Settings

Verifying IP Addressing and Routing

Verifying DNS Settings

Verifying Cisco Unified CM Settings

Cisco CallManager and TFTP Services Are Not Running

Creating a New Configuration File

Registering the Phone with Cisco Unified CM

Identifying Error Messages

As the phone cycles through the startup process, you can access status messages that may 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.

Checking Network Connectivity

If the network is down between the phone and the TFTP server or Cisco Unified CM, the phone cannot start up properly. Ensure that the network is currently running.

Verifying TFTP Server Settings

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.

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.

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.

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. For instructions, see Network Configuration Menu.

Verifying IP Addressing and Routing

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.

To verify these settings, look at the following options on the Settings > Network Configuration menu on the phone. (For information about displaying this menu, see Network Configuration Menu."

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. See Troubleshooting Switch Port Problems, available at this URL:

http://www.cisco.com/warp/customer/473/53.shtml

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. For instructions, see Network Configuration Menu.

If you are using DHCP, check the IP addresses distributed by your DHCP server. 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

Verifying DNS Settings

If you are using DNS to refer to the TFTP server or to Cisco Unified CM, you must ensure that you have specified a DNS server. Verify this setting by looking at the DNS Server 1 option on the Settings > Network Configuration menu on the phone. (For information about displaying this menu, see Displaying a Configuration Menu.) You should also verify that there is a CNAME entry in the DNS server for the TFTP server and for the Cisco Unified CM system.

You must also ensure that DNS is configured to do reverse look-ups.

Verifying Cisco Unified CM Settings

On the Cisco Unified IP Phone, press the Settings button, choose Device Configuration, and look at the CM Configuration options. (For information about displaying this menu, see Network Configuration Menu.) The Cisco Unified IP Phone attempts to open a TCP connection to all the Cisco Unified CM servers that are part of the assigned Cisco Unified CM group. If none of these options contain IP addresses or show Active or Standby, the phone is not properly registered with Cisco Unified CM. For tips on resolving this problem, see Registering the Phone with Cisco Unified CM.

Cisco CallManager and TFTP Services Are Not Running

If the Cisco Unified CM or TFTP services are not running, phones may not be able to start up properly. However, in such a situation, it is likely that you are experiencing a system-wide failure, and other phones and devices are unable to start up properly.

If the Cisco CallManager 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.


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 CM Administration, choose Cisco Unified Serviceability from the Navigation drop-down list, and click Go.

Step 2 Choose Tools > Control Center - Network Services.

Step 3 Choose the primary Cisco Unified CM 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 stop or start a service.

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

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


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 may be corrupted.

To create a new configuration file, follow these steps:

Procedure


Step 1 From Cisco Unified CM, choose Device > Phone > Find to locate the phone experiencing problems.

Step 2 Choose Delete to remove the phone from the Cisco Unified CM database.

Step 3 Add the phone back to the Cisco Unified CM database. For details, see Adding Phones to Cisco Unified CM.

Step 4 Power cycle the phone.



NoteWhen you remove a phone from the Cisco Unified CM database, its configuration file is deleted from the Cisco Unified CM TFTP server. The phone's directory number or numbers remain in the Cisco Unified CM 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 CM 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 CM 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.


Registering the Phone with Cisco Unified CM

A Cisco Unified IP Phone can register with a Cisco Unified CM server only if the phone has been added to the server or if auto-registration is enabled. Review the information and procedures in Adding Phones to Cisco Unified CM to ensure that the phone has been added to the Cisco Unified CM database.

To verify that the phone is in the Cisco Unified CM database, choose Device > Phone > Find from Cisco Unified CM Administration to search for the phone based on its MAC Address. For information about determining a MAC address, see Determining the MAC Address for a Cisco Unified IP Phone.

If the phone is already in the Cisco Unified CM database, its configuration file may be damaged. For assistance, see Creating a New Configuration File.

Symptom: Cisco Unified IP Phone Unable to Obtain IP Address

If a phone is unable to obtain an IP address when it starts up, the phone may be not be on the same network or VLAN as the DHCP server, or the switch port to which the phone is connected may be disabled.

Make sure that the network or VLAN to which the phone is connected has access to the DHCP server, and make sure that the switch port is enabled.

Symptom: The Cisco Unified IP Phone Displays the Message Security Error

When Cisco Unified IP Phones boot, the phone 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.

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 Performing a 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 CM 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 CM. These sections can help you identify the cause of a phone resetting in your network:

Verifying Physical Connection

Identifying Intermittent Network Outages

Verifying DHCP Settings

Checking Static IP Address Settings

Verifying Voice VLAN Configuration

Verifying that the Phones Have Not Been Intentionally Reset

Eliminating DNS or Other Connectivity Errors

Checking Power Connection

Verifying Physical Connection

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

Identifying Intermittent Network Outages

Intermittent network outages affect data and voice traffic differently. Your network may have been 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 its network connection.

If you are experiencing problems with the voice network, you should investigate whether an existing problem is simply being exposed.

Verifying DHCP Settings

Follow this process to help determine if the phone has been properly configured to use DHCP:

1. Verify that you have properly configured the phone to use DHCP. For more information, see Network Configuration Menu.

2. Verify that the DHCP server has been set up properly.

3. Verify the DHCP lease duration. We recommend 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.

Checking Static IP Address Settings

If the phone has been assigned a static IP address, verify that you have entered the correct settings. For more information, see Network Configuration Menu.

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

Isolating the phones on a separate auxiliary VLAN increases the quality of the voice traffic. For details, see Understanding How the Cisco Unified IP Phone Interacts with the VLAN.

Verifying that the Phones Have Not Been Intentionally Reset

If you are not the only administrator with access to Cisco Unified CM, you should verify that no one else has intentionally reset the phones.

You can check whether a Cisco Unified IP Phone received a command from Cisco Unified CM to reset by looking at the Network Statistics screen. (For information about displaying this screen, see Network Statistics Screen.) If the phone was recently reset one of these messages appears:

Reset-Reset—Phone recieved a Reset/Reset request from Cisco Unified CM Administration.

Reset-Restart—Phone recieved a Reset/Restart request from Cisco Unified CM Administration.

Eliminating DNS or Other Connectivity Errors

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. For details, see Resetting or Restoring the Cisco Unified IP Phone.

Step 2 Modify DHCP and IP settings:

a. Disable DHCP. For instructions, see Network Configuration Menu.

b. Assign static IP values to the phone. For instructions, see Network Configuration Menu. Use the same default router setting used for other functioning Cisco Unified IP Phones.

c. Assign TFTP server. See Network Configuration Menu. Use the same TFTP server used for other functioning Cisco Unified IP Phones.

Step 3 On the Cisco Unified CM server, verify that the local host files have the correct Cisco Unified CM server name mapped to the correct IP address.

Step 4 From Cisco Unified CM, 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 CM, 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 Determining the MAC Address for a Cisco Unified IP Phone.

Step 6 Power cycle the phone.


Checking Power Connection

In most cases, a phone will restart if it powers up using external power but loses that connection and switches to Power over Ethernet (PoE). Similarly, a phone may restart if it powers up using PoE and then gets connected to an external power supply.

Troubleshooting Cisco Unified IP Phone Security

Table 9-1 provides troubleshooting information for the security features on the Cisco Unified IP Phone. For information relating to the solutions for any of these issues, and for additional troubleshooting information about security, see the Cisco Unified Communications Manager Security Guide.

Table 9-1 Cisco Unified IP Phone Security Troubleshooting 

Problem
Possible Cause
CTL File Problems

Device authentication error.

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

Phone cannot authenticate CTL file.

The security token that signed the updated CTL file does not exist in the CTL file on the phone.

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

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

Phone does not register with Cisco Unified CM.

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

Phone does not request signed configuration files.

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

802.1X Enabled on Phone but Not Authenticating

Phone cannot obtain a DHCP-assigned IP address.

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

1. Verify that you have properly configured the required components. See Supporting 802.1X Authentication for the Cisco Unified IP Phone.

2. Confirm that the shared secret is configured on the phone. See 802.1X Authentication and Status.

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.

Phone does not register with Cisco Unified CM.

Phone status display as "Configuring IP" or "Registering".

802.1X Authentication Status displays as "Held" (For details, see 802.1X Authentication and Status.)

Status menu displays 802.1X status as "Failed" (For details, see Status Menu.)

802.1X Not Enabled

Phone cannot obtain a DHCP-assigned IP address

These errors typically indicate that 802.1X authentication is not enabled on the phone. To enable it, see 802.1X Authentication and Status.

Phone does not register with Cisco Unified CM

Phone status display as "Configuring IP" or "Registering"

802.1X Authentication Status displays as "Disabled"

Status menu displays DHCP status as timing out

Factory Reset Deleted 802.1X Shared Secret

Phone cannot obtain a DHCP-assigned IP address

These errors typically indicate that the phone has completed a factory reset while 802.1X was enabled. (See Performing a Factory Reset.) A factory reset deletes the shared secret, which is required for 802.1X authentication and network access. To resolve this, you have two options:

Temporarily disable 802.1X authentication 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.)

Phone does not register with Cisco Unified CM

Phone status display as "Configuring IP" or "Registering"

Cannot access phone menus to verify 802.1X status


General Troubleshooting Tips

Table 9-2 provides general troubleshooting information for the Cisco Unified IP Phone.

Table 9-2 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.

Poor quality when calling digital mobile phones using the G.729 protocol

In Cisco Unified CM, 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 mobile phone will have poor voice quality. Use G.729 only when absolutely necessary.

Prolonged broadcast storms cause IP phones to reset, or be unable to make or answer a call

A prolonged Layer 2 broadcast storm (lasting several minutes) on the voice VLAN may cause IP phones to reset, lose an active call, or be unable to initiate or answer a call. Phones may not come up until a broadcast storm ends.

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 affect their network connectivity. You must unlock the network configuration options before you can configure them. For details, see Unlocking and Locking Options.

Display issues

If the display appears to have rolling lines or a wavy pattern, it may be interacting with older fluorescent lights in the building. Moving the phone away from the lights, or replacing the lights, should resolve the problem.

Dual-Tone Multi-Frequency (DTMF) delay

When you are on a call that requires keypad input, if you press the keys too quickly, some of them may not be recognized.

Codec mismatch between the phone and another device

The RxType and the TxType statistics show the codec that is being used for a conversation between this Cisco Unified IP Phone and the other device. The values of these statistics should match. If they do not, verify that the other device can handle the codec conversation, or a transcoder is in place to handle the service.

For information about displaying these statistics, see Call Statistics Screen.

Sound sample mismatch between the phone and another device

The RxSize and the TxSize statistics show the size of the voice packets that are being used in a conversation between this Cisco Unified IP Phone and the other device. The values of these statistics should match.

For information about displaying these statistics, see Call Statistics Screen.

Gaps in voice calls

Check the AvgJtr and the MaxJtr statistics. A large variance between these statistics may indicate a problem with jitter on the network or periodic high rates of network activity.

For information about displaying these statistics, see Call Statistics Screen.

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 the power supply is disconnected

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

HALF_DUX_COLLISION_EXCEED_THRESHOLD

To resolve this problem, re-enable the port from the switch.

One-way audio

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

Peer to peer image distribution fails

If the peer to peer image distribution fails, the phone defaults 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 that are sent to the phone log.

Phone call cannot be established

The phone does not have a DHCP IP address, is unable to register to Cisco Unified CM, and shows a Configuring IP or Registering message.

Verify the following:

The Ethernet cable is attached.

The Cisco CallManager service is running on the Cisco Unified CM server.

Both phones are registered to the same Cisco Unified CM.

Audio server debug and capture logs are enabled for both phones. If needed, enable Java debug.

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.

Check the following using the Cisco Unified CM 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.

Capture a sniffer trace between the phone and Cisco Unified CM 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 CM configuration.

Enable audio server debug and capture logs from both phones. If needed, enable Java debug.


Resetting or Restoring the Cisco Unified IP Phone

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

Performing a Basic Reset

Performing a Factory Reset

Performing a 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.

Table 9-3 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 9-3 Basic Reset Methods 

Operation
Performing
Explanation

Restart phone

From the Main screen, press Settings to displays the Settings menu, then press **#**.

Note This factory reset sequence also works from any other screen that does not accept user input.

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 Unlocking and Locking Options.) Choose Network Configuration, press the More softkey, then press the Erase softkey.

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


Performing a 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

LSC—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 term70.default.loads file or the term71.default.loads file, depending on the phone model.

Before you perform a factory reset, ensure that the following conditions are met:

The phone must be on a DHCP-enabled network.

A valid TFTP server must be set in DHCP option 150 or option 66 on the DHCP server.

The term70.default.loads file or the term71.default.loads file and the files specified in that file should be available on the TFTP server that is specified by the DHCP packet.

To perform a factory reset of a phone, perform the following steps:

Procedure


Step 1 Unplug the power cable from the phone and then plug the cable back in.

The phone begins its power up cycle.

Step 2 While the phone is powering up, and before the Speaker button flashes on and off, press and hold #.

Continue to hold # until each line button flashes on and off in sequence in amber.

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 line buttons on the phone flash amber and then green, and the phone goes through the factory reset process. This process can take several minutes.

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


Using the 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 CM installation.

You can configure users' Cisco Unified IP Phones with QRT. When you do so, users can report problems with phone calls by pressing the QRT softkey. 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 the QRT softkey, 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 whether the destination device is a Cisco Unified IP Phone.

For more information about using QRT, see the Cisco Unified Communications Manager Features and Services 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 the following statistical metrics that are based on concealment events. The 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 interaval conceal every three 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 Trasmission Quality (CVTQ) index, to produce MOS LQK scores. Depending on the MOS LQK version number, these scores may 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.

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.

For information about configuring voice-quality metrics for phones, see the Cisco Unified Communications Manager System Guide, Cisco Unified IP Phones.

You can access voice quality metrics from the Cisco Unified IP Phone by using the Call Statistics screen (see Call Statistics Screen) or remotely by using Streaming Statistics. (See Chapter 8 "Monitoring the Cisco Unified 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 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


NoteCVTQ 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.

Troubleshooting Tips

When you observe significant and persistent changes to metrics, use Table 9-4 for general troubleshooting information.

Table 9-4 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 if the phone is using a different codec than expected (RxType and TxType).

Check to see if 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 mobile network or calling card network.

Acoustic problems coming from a speakerphone, hands-free mobile 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.


Where to Go for More Troubleshooting Information

If you have additional questions about troubleshooting the Cisco Unified IP Phones, several Cisco.com web sites can provide you with more tips. Choose from the sites available for your access level.

Cisco Unified IP Phone Troubleshooting Resources:

http://www.cisco.com/en/US/products/hw/phones/ps379/tsd_products_
support_series_home.html

Cisco Products and Services (Technical Support and Documentation):

http://www.cisco.com/en/US/products/sw/voicesw/tsd_products_support_
category_home.html

Cleaning the Cisco Unified IP Phone

To clean your Cisco Unified IP Phone, use a soft, dry cloth to wipe the phone and the 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.