Cisco Unified IP Phone 6921, 6941, and 6961 Administration Guide for Cisco Unified Communications Manager 7.1 (SCCP)
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 Communications Manager

Identifying Error Messages

Checking Network Connectivity

Verifying TFTP Server Settings

Verifying IP Addressing and Routing

Verifying DNS Settings

Cisco CallManager and TFTP Services Are Not Running

Creating a New Configuration File

Registering the Phone with Cisco Unified Communications Manager

Symptom: Cisco Unified IP Phone Unable to Obtain IP Address

Cisco Unified IP Phone Resets Unexpectedly

Verifying the Physical Connection

Identifying Intermittent Network Outages

Verifying DHCP Settings

Checking Static IP Address Settings

Verifying the Voice VLAN Configuration

Verifying that the Phones Have Not Been Intentionally Reset

Eliminating DNS or Other Connectivity Errors

Checking Power Connection

General Troubleshooting Tips

Resetting or Restoring the Cisco Unified IP Phone

Performing a Basic Reset

Performing a Factory Reset

Monitoring the Voice Quality of Calls

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 IP Phone or with your IP telephony network. It also explains how to clean and maintain your phone.

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

General Troubleshooting Tips

Resetting or Restoring the Cisco Unified IP Phone

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 Communications Manager, the phone should start up as described in the "Verifying the Phone Startup Process" section. 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 Communications Manager

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" section and the LCD 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.

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 the "Performing a Factory Reset" section.

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.

Symptom: The 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:

Identifying Error Messages

Checking Network Connectivity

Verifying TFTP Server Settings

Verifying IP Addressing and Routing

Verifying DNS Settings

Cisco CallManager and TFTP Services Are Not Running

Creating a New Configuration File

Checking Network Connectivity

In addition, problems with security may prevent the phone from starting up properly. See the "General Troubleshooting Tips" section for more information.

Identifying Error Messages

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 the "Status Messages Screen" section 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 Communications Manager, 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 Applications button, then selecting Admin Settings > Network Configuration > IPv4 > TFTP Server 1.

If you have assigned a static IP address to the phone, you must manually enter a setting for the TFTP Server 1 option. See the "Network Setup Menu" section.

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. See the "Network Setup Menu" section for instructions.

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.

On the Cisco Unified IP Phone, press the Applications button, then select Administrator Settings > Network Configuration > IPv4, and look at the following options:

Boot/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. Refer to the Troubleshooting Switch Port and Interface Problems document, available at this URL:
http://www.cisco.com/en/US/customer/products/hw/switches/ps700/products_tech_note09186a008015bfd6.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. See the "Network Setup Menu" section for instructions.

If you are using DHCP, check the IP addresses distributed by your DHCP server. Refer to the Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks document, available at this URL:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a00800f0804.shtml

Verifying DNS Settings

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. Verify this setting by pressing the Applications button, then selecting Administrator Settings > Network Configuration > IPv4 > DNS Server 1. 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.

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

Cisco CallManager and TFTP Services Are Not Running

If the Cisco CallManager 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.

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 its radio button and then click the Start button.

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



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


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 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 the "Adding Phones to the Cisco Unified Communications Manager Database" section for details.

Step 4 Power cycle the phone.


NoteWhen 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's 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. Refer to Cisco Unified Communications Manager Administration Guide for more information.

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.


Registering the Phone with Cisco Unified Communications Manager

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 auto-registration is enabled and if there are sufficient number of unit licenses. Review the information and procedures in the "Adding Phones to the Cisco Unified Communications Manager Database" section 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 the "Determining the MAC Address for a Cisco Unified IP Phone" section.

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

For more information on licensing go to the Licenses for Phones section in the Cisco Unified Communications Manager System Guide

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.

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:

Verifying the Physical Connection

Identifying Intermittent Network Outages

Verifying DHCP Settings

Checking Static IP Address Settings

Verifying the Voice VLAN Configuration

Verifying that the Phones Have Not Been Intentionally Reset

Eliminating DNS or Other Connectivity Errors

Verifying the 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 might 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

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 the "Network Setup Menu" section 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 it to 8 days.

Checking Static IP Address Settings

If the phone has been assigned a static IP address, verify that you have entered the correct settings. See the "Network Setup Menu" section for more information.

Verifying the 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 the same switch as the 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. See the "Understanding How the Cisco Unified IP Phone Interacts with the VLAN" section 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.

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

Reset-Reset—Phone closed due to receiving a Reset/Reset from Cisco Unified Communications Manager Administration.

Reset-Restart—Phone closed due to receiving a Reset/Restart from Cisco Unified Communications Manager 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 Reset Settings menu to reset phone settings to their default values. See the "Resetting or Restoring the Cisco Unified IP Phone" section for details.

Step 2 Modify DHCP and IP settings:

a. Disable DHCP. See the "Network Setup Menu" section for instructions.

b. Assign static IP values to the phone. See the "Network Setup Menu" section for instructions. Use the same default router setting used for other functioning Cisco Unified IP Phones.

c. Assign a TFTP server. See the "Network Setup Menu" section 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.

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 > Find and verify that you have assigned the correct MAC address to this Cisco Unified IP Phone. For information about determining a MAC address, see the "Determining the MAC Address for a Cisco Unified IP Phone" section.

Step 6 Power cycle the phone.


Checking Power Connection

In most cases, a phone will restart 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 gets connected to an external power supply.

General Troubleshooting Tips

Table 9-1 provides general troubleshooting information for the Cisco Unified IP Phone.

Table 9-1 Cisco Unified IP Phone Troubleshooting 

Summary
Explanation

Connecting a Cisco Unified IP Phone to another Cisco Unified IP Phone/

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 (by using the PC port), the phones will not work.

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

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. 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 computer's network card 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 the "Unlocking and Locking Options" section 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.

LCD display issues.

If the display appears to have rolling lines or a wavy pattern, it might be interacting with certain types of 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 might 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 that a transcoder is in place to handle the service.

See the "Call Statistics Screen" section for information about displaying these statistics.

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.

See the "Call Statistics Screen" section for information about displaying these statistics.

Gaps in voice calls.

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

See the "Call Statistics Screen" section for information about displaying these statistics.

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 (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, 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 configured.

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:

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.

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


Resetting or Restoring the Cisco Unified IP Phone

There are two general 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 9-2 describes the ways to perform a basic reset. You can reset a phone with any of these operations after the phone has started up. Choose the operation that is appropriate for your situation.

Table 9-2 Basic Reset Methods 

Operation
Performing
Explanation

Restart phone

Press the Services, Settings, or Directories button and then 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.

Reset Settings

From the Admin Settings menu, unlock phone options (see the "Unlocking and Locking Options" section), then choose Reset Settings > All Settings.

Resets user and network configuration settings to their default values, and restarts the phone.

From the Admin Settings menu, unlock phone options (see the "Unlocking and Locking Options" section), then choose Reset Settings > Network Settings.

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

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 (phone recovers by using the image in the inactive partition of flash to boot up).

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.

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 it 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 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.


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.

Concealment Ratio metrics—Show the ratio of concealment frames over total speech frames. An interval conceal ratio is calculated every 3 seconds.

Concealed Second metrics—Show 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.


Note Concealment ratio and concealment seconds are primary measurements based on frame loss. A Conceal Ratio of zero indicates that the IP network is delivering frames and packets on time with no loss.


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

Troubleshooting Tips

When you observe significant and persistent changes to metrics, use Table 9-3 for general troubleshooting information.

Table 9-3 Changes to Voice Quality Metrics

Metric Change
Condition

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.


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_troubleshoot_and_alerts.html

Cisco Products and Services (Technical Support and Documentation):

http://www.cisco.com/en/US/products/ps10326/tsd_products_support_series_home.html

Cleaning the Cisco Unified IP Phone

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