Troubleshooting the Cisco Unified IP Phone
Cisco Unified IP Phones provide information that can assist you in troubleshooting problems with your Cisco Unified IP Phone or in your IP telephony network.
This chapter includes the following sections:
•Resolving Startup Problems
•Cisco Unified IP Phone Resets Unexpectedly
•General Troubleshooting Tips for the Cisco Unified IP Phone
•Logging Information for Troubleshooting
•Resetting the Cisco Unified IP Phone
•Using the nptcap Tool
•Where to Go for More Troubleshooting Information
•Cleaning the Cisco Unified IP Phone
Resolving Startup Problems
After installing a Cisco Unified IP Phone on your network and adding it to Cisco Unified CallManager, 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 Start Up Process
•Symptom: The Cisco Unified IP Phone Does Not Register with Cisco Unified CallManager
•Cisco Unified IP Phone Resets Unexpectedly
Note Any procedures that refer to an LCD screen display problem apply only to the Cisco Unified IP Phone 7905G and 7912G.
Symptom: The Cisco Unified IP Phone Does Not Go Through its Normal Start Up Process
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. 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 that 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:
–Verify that the electrical outlet is functional.
–If you are using in-line power, try using the external power supply instead.
–If you are using the external power supply, switch with a unit that you know to be functional.
If, after attempting these solutions, the phone still does not start up, contact a Cisco technical support representative for additional assistance.
Symptom: The Cisco Unified IP Phone Does Not Register with Cisco Unified CallManager
If a phone proceeds past the first stage (LED buttons flashing on and off), and, on a Cisco Unified IP Phone 7905G and 7912G, 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 CallManager server.
These sections can assist you in determining the reason the phone is unable to start up properly:
•Registering the Phone with Cisco Unified CallManager
•Checking Network Connectivity
•Verifying TFTP Server Settings
•Verifying IP Addressing and Routing
•Verifying DNS Settings
•Verifying Cisco Unified CallManager Settings
•Cisco Unified CallManager and TFTP Services Are Not Running
•Creating a New Configuration File
Registering the Phone with Cisco Unified CallManager
A Cisco Unified IP Phone can register with a Cisco Unified CallManager server only if the phone has been added to the server or if auto-registration for SIP is enabled. Review the information and procedures in the "Adding Phones to the Cisco Unified CallManager Database" section to ensure that the phone has been added to the Cisco Unified CallManager database.
To verify that the phone is in the Cisco Unified CallManager database, choose Device > Phone > Find from Cisco Unified CallManager Administration to search for the phone based on its MAC Address. (To determine the MAC address of a phone, see the "Determining the MAC Address of a Cisco Unified IP Phone" section.)
If the phone is already in the Cisco Unified CallManager database, its configuration file may be damaged. See the "Creating a New Configuration File" section for assistance.
Checking Network Connectivity
If the network is down between the phone and the TFTP server or Cisco Unified CallManager, the phone cannot start up properly. Ensure that the network is currently running.
Verifying TFTP Server Settings
The Cisco Unified IP Phone uses the TFTP server setting to identify the primary TFTP server used by the phone. If this setting is incorrect, the Cisco Unified IP Phone may continually cycle while attempting to contact the identified TFTP Server.
If you have assigned a static IP address to the phone, you must manually enter this setting.
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 information about determining and changing TFTP server settings, see "Configuring Settings on the Cisco Unified IP Phone," or "Reference List of Parameters."
Verifying IP Addressing and Routing
You should verify the IP addressing and routing settings for the Cisco Unified IP 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.
Check for the following problems:
•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 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. See Table 4-2.
If you are using DHCP, check the IP addresses distributed by your DHCP server. Refer to Understanding and Troubleshooting DHCP in Catalyst Switch or Enterprise Networks, available at this URL: http://www.cisco.com/warp/customer/473/100.html#41
For information about determining and changing IP addressing and routing settings, see "Configuring Settings on the Cisco Unified IP Phone," or "Reference List of Parameters."
Verifying DNS Settings
If you are using a fully qualified domain name (FQDN) to refer to the TFTP server or to Cisco Unified CallManager, you must ensure that you have specified a DNS server. You should also verify that there is a CNAME entry in the DNS server for the TFTP server and for the Cisco Unified CallManager system.
For information about determining and changing DNS settings, see "Configuring Settings on the Cisco Unified IP Phone," or "Reference List of Parameters."
Verifying Cisco Unified CallManager Settings
The Cisco Unified IP Phone attempts to open a TCP connection to all the Cisco Unified CallManager servers that are part of the assigned Cisco Unified CallManager group. Take one of these actions to verify Cisco Unified CallManager settings:
•On the Cisco Unified IP Phone 7905G or 7912G, choose Settings > SIP Configuration and look at the SIP Proxy 1-4 options. (See "Configuring Settings on the Cisco Unified IP Phone.")
•On any phone model, display the Network Configuration area of the Cisco Unified IP Phone web page and look at the SIP Proxy 1-4 options. (See "Reference List of Parameters.")
If none of the Cisco Unified CallManager options contain IP addresses or show Active or Standby, the phone is not properly registered with Cisco Unified CallManager. See the "Registering the Phone with Cisco Unified CallManager" section for tips on resolving this problem.
Cisco Unified CallManager and TFTP Services Are Not Running
If the Cisco Unified CallManager or TFTP services are not running, phones may not be able to start up properly. However, in such situations, it is likely that you are experiencing a system-wide failure and that other phones and devices are unable to start up properly.
If the Cisco Unified 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 determine the status of a service, perform the following steps:
Step 1 From Cisco Unified CallManager Administration, choose Cisco CallManager Serviceability from the Navigation pull-down menu located in the upper-right portion of the main administration screen.
Step 2 Choose Tools > Control Center—Feature Services.
Step 3 From the Servers pull-down menu, choose the primary Cisco Unified CallManager server.
The page 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 the service radio button and then click the Start button.
Creating a New Configuration File
If you continue to have problems with a particular phone that other suggestions in this chapter do not resolve, the configuration file might be corrupted.
To create a new configuration file, follow these steps:
Step 1 From Cisco Unified CallManager Administration, select Device > Phone > Find to locate the phone experiencing problems.
Step 2 Check the box corresponding to the phone, then click Delete Selected to remove the phone from the Cisco Unified CallManager database.
Step 3 Add the phone back to the Cisco Unified CallManager database. See the "Adding Phones to the Cisco Unified CallManager Database" section for details.
Step 4 Power cycle the phone.
Note When you remove a phone from the Cisco Unified CallManager database, its configuration file is deleted from the Cisco Unified CallManager TFTP server. The phone's directory number remains in the Cisco Unified CallManager database. Such a directory number is called an "unassigned DNs and can be used for other devices. If unassigned DNs are not used by other devices, delete them from the Cisco Unified CallManager database. You can use the Route Plan Report to view and delete unassigned reference numbers. Refer to Cisco Unified CallManager Administration Guide for more information.
Cisco Unified IP Phone Resets Unexpectedly
If users report that their phones are resetting during calls or resetting while idle on their desk, you should investigate the cause. If the network connection and Cisco Unified CallManager 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 CallManager. 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
Verifying Physical Connection
Verify that the Ethernet connection to which the Cisco Unified IP Phone is connected is up. For example, check if the particular port or switch to which the phone is connected is down.
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 procedure 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 Table 4-2 for details.
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.
Cisco Unified IP Phones send messages with request type 151 to renew their DHCP address leases. If the DHCP server expects messages with request type 150, the lease will be denied, forcing the phone to restart and request a new IP address from the DHCP server.
Checking Static IP Address Settings
If the phone has been assigned a static IP address, verify that you have entered the correct settings. See Table 4-2.
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. See the "Understanding How the Cisco Unified IP Phone Interacts with the Cisco Catalyst Family of Switches" section for details.
Verifying that the Phones Have Not Been Intentionally Reset
If you are not the only administrator with access to Cisco Unified CallManager, you should verify that no one else has intentionally reset the phones.
Eliminating DNS or Other Connectivity Errors
If the phone continues to reset, follow these steps to eliminate DNS or other connectivity errors:
Step 1 Reset the phone to factory defaults. See the "Resetting the Cisco Unified IP Phone" section for details.
Step 2 Modify DHCP and IP settings.
a. Disable DHCP. See Table 4-2 for details.
b. Assign static IP values to the phone. See Table 4-2 for details. Use the same default router setting used for other functioning Cisco Unified IP Phones.
c. Assign a TFTP server. See Table 4-2 for details. Use the same TFTP server used for other functioning Cisco Unified IP Phones.
Step 3 On the Cisco Unified CallManager server, verify that the local host files have the correct Cisco Unified CallManager server name mapped to the correct IP address.
Step 4 From Cisco Unified CallManager Administration, choose System > Server and verify that the server is referred to by its IP address or host name.
Step 5 From Cisco Unified CallManager, select Device > Phone and verify that you have assigned the correct MAC address to this Cisco Unified IP Phone.
To determine the MAC address of a phone, see the "Determining the MAC Address of a Cisco Unified IP Phone" section.
Step 6 Power cycle the phone.
General Troubleshooting Tips for the Cisco Unified IP Phone
Table 7-1 provides general troubleshooting information for the Cisco Unified IP Phones.
Table 7-1 Cisco Unified IP Phone Troubleshooting
Daisy-chaining IP phones
Do not connect an IP phone to another IP phone through the access port. Each IP phone should directly connect to a switch port. If you connect IP phones together in a line (daisy-chaining), a problem with one phone can affect all subsequent phones in the line. Also, all phones on the line share bandwidth.
Poor quality when calling digital cell phones using the G.729 protocol
In Cisco Unified CallManager, 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 re-register
Prolonged broadcast storms (lasting several minutes) on the voice VLAN cause the IP phones to re-register with another Cisco Unified CallManager server.
Moving a network connection from the phone to a workstation
If you are powering a 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.
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 "Accessing Network Configuration Settings through the Network Configuration Menu on the Phone" section for details.
The phone resets when it loses contact with the Cisco Unified CallManager 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.
Logging Information for Troubleshooting
You can collect information relating to the operations of the Cisco Unified IP Phone 7905G and 7912G and store this information in a log file on a server that you specify. If you experience a problem with a phone, this information can be useful for troubleshooting.
To collect information for troubleshooting, you will need the nprintf.exe tool. This tool is bundled with the Cisco Unified IP Phone software. You can also obtain this tool from the CCO website. It is included with the SIP Software Package Zip file.
To collect troubleshooting information in a log file, follow these steps:
Step 1 Press the Menu key on the phone.
Step 2 Select Settings > Network Configuration.
Step 3 If the menu is locked, press **# to unlock it.
Step 4 Press **3 to access the Device Logs screen.
Step 5 Enter the host server and port to which debug information should be sent.
For example, if you want degug information sent to port 9001 on a server whose IP address is 192.168.2.170, press 192*168*2*170*9001.
Step 6 Press Validate to save the setting.
Note And eye icon appears on the idle screen to indicate that logging has been enabled for the phone.
Step 7 On the server that will receive information, open a command window and type the following command:
where listen_port is the same port that you specified with the Nprintf parameter.
If you do not specify a port, 9001 is used by default.
While prserv is running, information from the Cisco Unified IP Phone is sent to a file named listen_port.log, where listen_port is the port you specified with the Nprintf parameter and the prserv command. This file is stored on the server you specified with the Nprintf parameter in the folder from which you ran the prserv command. If the file exists, new information is appended to it.
You can open a listen_port.log file using a text editor.
Step 8 To exit prserv.exe and stop collecting information, press Ctrl-C in the command window.
Note If you want to collect information from more than one Cisco Unified IP Phone, Cisco recommends that you store information in a separate listen-port.log file for each phone. If you store all information in a single file, it can be difficult to identify which messages belong to which phones. To generate separate listen-port.log files, configure each phone using the LCD screen on the phone. For each phone, use the Nprintf parameter in LCD screen to specify a unique port number on the server to which information will be sent. Then, run prserv.exe multiple times, once for each phone from which you want to collect information. Run each instance of preserv.exe in its own command window. For each instance, make sure to specify a port number that corresponds to a port number in a Nprintf parameter.
Using the nptcap Tool
The nptcap tool can help you to identify network problems that can degrade the quality of conversations over the Cisco Unified IP Phone 7905G and 7912G. If you have an account on CCO, you can download the nptcap.zip file from this URL:
The nptcap.zip file contains the nptcap tool and a Readme file that describes the tool in detail.
Resetting the Cisco Unified IP Phone
If you reset the phone, any changes made that have not been saved are lost and set back to default settings.
Follow these steps to reset the phone:
Step 1 Press **#** to reset the Cisco Unified IP Phone.
The phone displays "Do you want to reboot the phone?"
Step 2 Press the Yes softkey.
The phone cycles through normal startup procedures.
Erasing the Local Configuration
If you want to erase all locally stored configuration options, you can erase the configuration and restore settings to their default values, including enabling DHCP.
Erasing the local configuration removes all user-defined changes, except ringer sound, made locally on the Cisco Unified IP Phone. If you choose this option, these settings are set back to their default values.
To erase the local configuration, follow these steps:
Step 1 Press the Menu button.
Step 2 Choose Settings> Network Configuration.
Step 3 Perform either of these procedures:
–Press **2. The phone displays "Do you want to reset all system settings to default values?"
–Press the Yes softkey.
–Press **#. If the phone displays "Enter Admin Password," enter your password and then press the Enter softkey. Make sure that an unlocked padlock icon appears in the upper right corner of the LCD screen on the phone.
–Scroll to Erase Configuration.
–Press the Yes softkey and then press the Save softkey.
The phone cycles through normal startup procedures.
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.
•Cisco Unified IP Phone Troubleshooting Resources:
•Cisco Products and Services (Technical Support and Documentation):
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.