Chapter 9 Troubleshooting and Maintenance

Resolving Startup Problems

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

Verifying DNS Settings

If you are using DNS to refer to the TFTP server or to Cisco Unified CallManager, you must ensure that you have specified a DNS server. Verify this setting by pressing the Applications Menu button and selecting Settings > Network Configuration > 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 CallManager system.

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

Windows2000 is configured by default only to perform forward look-ups.

Verifying Cisco Unified CallManager Settings

On the Cisco Unified IP Phone, press the Applications Menu button and select Settings > Network Configuration > CallManager 15. 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. If none of these 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 on page 9-4for 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 a situation, 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.

 

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

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Cisco Systems 7906G, 7911G manual Verifying DNS Settings

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.