Cisco IP Phone 7905G Administration Guide for H.323
Troubleshooting the Cisco IP Phone 7905G

Table Of Contents

Troubleshooting the Cisco IP Phone 7905G

General Troubleshooting Tips

Symptoms and Actions

Installation and Upgrade Issues

Contacting TAC


Troubleshooting the Cisco IP Phone 7905G

This chapter describes some basic testing and troubleshooting procedures for the Cisco IP Phone 7905G. It contains the following sections:

General Troubleshooting Tips

Symptoms and Actions

Installation and Upgrade Issues

Contacting TAC


General Troubleshooting Tips

The suggestions in this section are general troubleshooting tips.

If using a Dynamic Host Configuration Protocol (DHCP) server, make sure that it is operating correctly. The DHCP server should show an incoming request from the MAC address listed on the product label.

If you do not see the status screen after you connect the Ethernet cable, make sure the power cord and the Ethernet connection are secure.

If you do not hear a dial tone, make sure that the telephone-handset line cord is plugged into the Cisco IP Phone 7905G phone port.

A fast-busy tone indicates that network connectivity between you and your called party may be temporarily down. Try your call again later.

If you place a call to another IP telephone, hear ringback, and the called party answers but you cannot hear the speaker's voice, verify that the Cisco IP Phone 7905G and the other IP telephone support at least one common audio codec: G.711 A-law, G.711 u-law, or G.729a.

If you use a firewall, make sure that it is a Cisco PIX firewall, Version 5 or later.

Symptoms and Actions

Symptom    Parameters with values set by means of the web interface or LCD menu screen revert to their original settings.

Possible Cause    You are using TFTP for provisioning (UseTFTP parameter is set to 1). The Cisco IP Phone 7905G has a cached profile stored in its Flash memory; this is what you see through the web interface and LCD menu screens. If the UseTFTP parameter is set to 1, the cached profile is synchronized with its profile located at the TFTP server. This synchronization update of the cache value happens at approximate intervals determined by the CFGInterval parameter's value or at power-up.

Recommended Action    If you are using TFTP to configure phones, do not use the web interface or LCD menu screens to modify any H.323 or network parameter values of the Cisco IP Phone 7905G profile. Use the web interface only to initially configure the address of the phone for later TFTP provisioning, as described in Chapter 3.

Symptom    Time is not displayed or is displayed incorrectly.

Possible Cause    A Network Time Protocol (NTP) server is not specified in the Cisco IP Phone 7905G configuration or the NTP server is returning an incorrect time.

Recommended Action    Specify at least one NTP server in the Cisco IP Phone 7905G configuration and check the NTP time server.

Symptom    There is a fast busy tone.

Possible Cause    User name or password is incorrect.

Recommended Action    Verify that the user name and password are as provided by your system administrator.

Installation and Upgrade Issues

Note The following issues apply to the manual upgrade process only. Image and language upgrades must be performed separately.

Symptom    Status screen does not display.

Possible Cause    The Cisco IP Phone 7905G is trying to obtain the DHCP address or the software image is being upgraded.

Possible Cause    The Ethernet cable is unplugged.

Recommended Action    Wait for a few moments or plug in the Ethernet cable.

Symptom    There is no dial tone.

Possible Cause    No user ID was entered.

Recommended Action    Enter the correct user ID.

Symptom    There is an incorrect dial tone.

Possible Cause    You have installed a template for a country other than your own. Check the web interface for your dial plan. The default is U.S.

Recommended Action    Install the correct country template.

Contacting TAC

If you need to contact the Cisco Technical Assistance Center (TAC), see the "Obtaining Technical Assistance" section and be prepared to provide the following information:

Product codes

Software version number, hardware version number, and serial number—To identify these numbers, use the services menu on the Cisco IP Phone 7905G:

MAC address of the Cisco IP Phone 7905G

To identify the software version number, hardware version number, and serial number, follow these steps:

Step 1 Press the Services key.

Step 2 Use the navigation button or keypad digit to select Settings and press the Select softkey.

Step 3 Use the navigation button or keypad digit to select Status and press the Select softkey.

Step 4 Use the navigation button or keypad digit to select Firmware Versions and press the Select softkey.


A debugging tool, prserv, is available from TAC. Use prserv in conjunction with the NPrintf configuration parameter. Contact Cisco for more information. See the "Obtaining Technical Assistance" section in the Preface for instructions.

You should also have access to a "sniffer" or LAN analyzer.

Caution For security reasons, Cisco recommends that you do not use the web interface over the public network. Disable the web interface by setting the OpFlags parameter bit 7 (mask 0x80) to 1 before the phone leaves the service-provider site. After the parameter bit is set, limited configuration can be done by means of the LCD menu screens; full configuration can be done by means of the TFTP server.