Chapter 9 Troubleshooting and Maintenance

Cisco Unified IP Phone Resets Unexpectedly

Eliminating DNS or Other Connectivity Errors

If the phone continues to reset, follow these steps to eliminate DNS or other connectivity errors:

Step 1 Use the Erase softkey to reset phone settings to their default values. See the “Resetting or Restoring the Cisco Unified IP Phone” section on page 9-15for details.

Step 2 Modify DHCP and IP settings.

a.Disable DHCP. See the “Network Configuration Menu” section on page 4-7 for instructions.

b.Assign static IP values to the phone. See the “Network Configuration Menu” section on page 4-7for instructions. Use the same default router setting used for other functioning Cisco Unified IP Phones.

c.Assign TFTP server. See the “Network Configuration Menu” section on page 4-7 for instructions. 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. Refer to Configuring The IP Hosts File on a Windows 2000 CallManager Server, available at this URL: http://www.cisco.com/warp/customer/788/AVVID/cm_hosts_file.html

Step 4 From Cisco Unified CallManager, 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 CallManager, 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 the “Determining the MAC Address of a Cisco Unified IP Phone” section on page 2-15.

Step 6 Power cycle the phone.

 

 

Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified CallManager

 

 

 

 

 

 

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Cisco Systems 7911G, 7906G manual Eliminating DNS or Other Connectivity Errors

7906G, 7911G specifications

The Cisco Systems 7911G is a versatile IP phone designed to enhance communication in enterprise environments. Targeting workers in various organizational settings, this model is known for its reliability, ease of use, and robust features that cater to both basic and advanced telephony requirements.

One of the key features of the Cisco 7911G is its support for Voice over IP (VoIP) technology. Using this technology allows for the transmission of voice signals over the internet rather than through traditional telephone lines. This not only reduces telephony costs but also offers enhanced functionality that integrates seamlessly with existing communication systems.

The phone is equipped with a monochrome graphical display that provides users with clear visibility of their call status, directory information, and menu options. With a resolution of 128x64 pixels, the screen is large enough to offer important information without overwhelming the user. This simplicity makes it an ideal choice for users who require straightforward functionality without the complexity of advanced features.

Ergonomically designed, the Cisco 7911G features a comfortable keypad with dedicated buttons for frequently used functions such as mute, hold, and transfer. It supports multiple lines, providing users with the ability to manage multiple calls simultaneously. Additionally, it offers programmable line keys that can be customized for speed dial or as soft keys for quick access to features.

The device supports Power over Ethernet (PoE), which allows the phone to receive power through the network cable rather than needing a separate power source. This feature not only simplifies installation but also enhances mobility within the workspace, as it reduces cable clutter.

Another significant characteristic of the Cisco 7911G is its compatibility with Cisco Unified Communications Manager, which ensures centralized management of telephony systems. It also supports a range of audio codecs that help in delivering high-quality audio during calls, reducing latency and improving overall communication quality.

Security is also a focus with the Cisco 7911G, as it features a secure access feature that includes Transport Layer Security (TLS) and Secure Real-Time Transport Protocol (SRTP) for encrypted voice communications. This ensures that sensitive conversations are protected from eavesdropping.

Overall, the Cisco Systems 7911G is a reliable, feature-rich IP phone that provides an excellent solution for organizations looking to upgrade their communication systems. Its combination of user-friendly design, powerful integrations, and security features makes it a cornerstone in the suite of Cisco telecommunications solutions.