Chapter 9 Troubleshooting and Maintenance

General Troubleshooting Tips

Table 9-1 Cisco Unified IP Phone Security Troubleshooting (continued)

Problem

Possible Cause

Factory Reset Deleted 802.1X Shared Secret

Phone cannot obtain a DHCP-assigned IP address

Phone does not register with

Cisco Unified Communications Manager

Phone status display as “Configuring IP” or “Registering”

Cannot access phone menus to verify 802.1X status

These errors typically indicate that the phone has completed a factory reset (see the “Performing a Factory Reset” section on page 9-14) while 802.1X was enabled. 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.

Once 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 the “802.1X Authentication and Status” section on page 4-31).

General Troubleshooting Tips

Table 9-2provides 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 (by using the

 

PC port), the phones will not work.

 

 

Poor quality when calling mobile

In Cisco Unified Communications Manager, you can configure the

phones using the G.729 protocol

network to use the G.729 protocol (the default is G.711). When

 

using G.729, calls between an IP phone and a mobile phone will

 

have poor voice quality. Use G.729 only when absolutely necessary.

 

 

Prolonged broadcast storms

A prolonged Layer 2 broadcast storm (lasting several minutes) on

cause IP phones to reset, or be

the voice VLAN may cause IP phones to reset, lose an active call,

unable to make or answer a call

or be unable to initiate or answer a call. Phones may not come up

 

until a broadcast storm ends.

 

 

 

Cisco Unified IP Phone 7970G/7971G-GE Administration Guide for Cisco Unified Communications Manager 7.0

9-10

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Cisco Systems 7970G, 7971G-GE manual General Troubleshooting Tips, Summary Explanation
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7970G, 7971G-GE specifications

The Cisco Systems 7971G-GE is a sophisticated IP phone designed for enterprise communication, offering a range of features that enhance productivity and collaboration. As part of the Cisco Unified Communications portfolio, this phone is known for its impressive technology and reliable performance.

One of the main features of the 7971G-GE is its high-resolution color display. The 5-inch LCD screen provides users with a visually appealing and intuitive interface, allowing for easy navigation through menus and contacts. The phone supports up to six lines, making it ideal for users who require multiple lines for simultaneous calls. Users can effortlessly manage calls with the ability to switch between lines and access important call features like hold, transfer, and conference calling.

In terms of audio quality, the Cisco 7971G-GE is equipped with high-definition voice technology. This feature ensures crystal-clear sound during calls, reducing background noise and enhancing the clarity of conversations. The phone also supports wideband audio codecs, enabling a richer voice experience that is particularly valuable in business environments.

The phone is designed with user convenience in mind. It offers programmable buttons that can be customized to suit individual needs, allowing easy access to frequently used functions or contact lists. Additionally, the presence indicator feature lets users see the availability of their colleagues in real-time, promoting more effective communication and collaboration.

Networking capabilities are another strong point of the Cisco 7971G-GE. The phone supports both Power over Ethernet (PoE) and standard Ethernet connectivity. This enables easy deployment without the need for additional power outlets. Moreover, the device is compatible with various Cisco communication platforms, integrating seamlessly with existing Cisco infrastructure, which is essential for businesses looking to upgrade their communications systems.

Security is a crucial consideration for modern enterprises, and Cisco addresses this with robust encryption features that protect voice and video calls. The phone supports secure signaling and media encryption, ensuring that sensitive conversations remain confidential.

Overall, the Cisco Systems 7971G-GE is a feature-rich IP phone that combines advanced technology with user-friendly design. Its high-definition audio, customizable features, and seamless integration with Cisco networks make it a popular choice for businesses seeking to improve their communication systems. With its reliability and performance, the Cisco 7971G-GE continues to support effective collaboration in an increasingly connected world.
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