Chapter 7 Troubleshooting and Maintenance

General Troubleshooting Tips

Table 7-1

Cisco Unified IP Phone Troubleshooting (continued)

 

 

 

Summary

 

Explanation

 

 

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

 

 

the Phone Configuration Settings” section on page 4-2for details.

 

 

 

Phone resetting.

 

The phone resets when it loses contact with the Cisco Unified Communications

 

 

Manager software. This lost connection can be due to any network connectivity

 

 

disruption, including cable breaks, switch outages, and switch reboots.

 

 

Dual-Tone Multi-Frequency (DTMF)

When you are on a call that requires keypad input, if you press the keys too quickly,

delay.

 

some of them might not be recognized.

 

 

Codec mismatch between the phone

The RxType and the TxType statistics show the codec that is being used for a

and another device.

conversation between this Cisco Unified IP phone and the other device. The values

 

 

of these statistics should match. If they do not, verify that the other device can

 

 

handle the codec conversation, or that a transcoder is in place to handle the service.

 

 

Sound sample mismatch between the

The RxSize and the TxSize statistics show the size of the voice packets that are

phone and another device.

being used in a conversation between this Cisco Unified IP phone and the other

 

 

device. The values of these statistics should match.

 

 

Gaps in voice calls.

Check the AvgJtr and the MaxJtr statistics. A large variance between these statistics

 

 

might indicate a problem with jitter on the network or periodic high rates of network

 

 

activity.

 

 

Loopback condition.

A loopback condition can occur when the following conditions are met:

 

 

• The SW Port Configuration option in the Network Configuration menu on the

 

 

phone is set to 10 Half

 

 

(10-BaseT / half duplex)

 

 

• The phone receives power from an external power supply

 

 

• The phone is powered down (the power supply is disconnected)

 

 

In this case, the switch port on the phone can become disabled and the following

 

 

message will appear in the switch console log:

 

 

HALF_DUX_COLLISION_EXCEED_THRESHOLD

 

 

To resolve this problem, re-enable the port from the switch.

 

 

 

One-way audio.

 

When at least one person in a call does not receive audio, IP connectivity between

 

 

phones is not established. Check the configurations in routers and switches to ensure

 

 

that IP connectivity is properly configured.

 

 

Phone call cannot be established.

The phone does not have a DHCP IP address, is unable to register to Cisco Unified

 

 

Communications Manager, and shows a Configuring IP or Registering message.

 

 

Verify the following:

 

 

1. The Ethernet cable is attached.

 

 

2. The Cisco CallManager service is running on the Cisco Unified

 

 

Communications Manager server.

 

 

3. Both phones are registered to the same Cisco Unified Communications

 

 

Manager.

 

 

4. Audio server debug and capture logs are enabled for both phones. If needed,

 

 

enable Java debug.

 

 

 

Cisco Unified IP Phone 6901 and 6911 Administration Guide for Cisco Unified Communications Manager 8.5 (SCCP and SIP)

 

OL-23874-01

7-9

 

 

 

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Image 99
Cisco Systems 6901 manual Phone Configuration Settings section on page 4-2for details, Halfduxcollisionexceedthreshold
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6901 specifications

Cisco Systems 6901 is a versatile, compact, and powerful router designed to meet the networking needs of small to medium-sized businesses, as well as enterprise branch offices. This model is part of Cisco's ISR (Integrated Services Router) portfolio, which is known for its capability to integrate multiple services into a single platform, ensuring high efficiency and cost-effectiveness.

One of the main features of the Cisco 6901 is its ability to support advanced routing protocols, including RIP, EIGRP, OSPF, and BGP. This versatility allows for seamless integration into various network architectures, facilitating efficient communication and data transfer across multiple locations. The device is also built to handle high-bandwidth applications, making it an ideal choice for businesses that rely on robust network performance.

In terms of connectivity, Cisco 6901 offers multiple Ethernet ports, supporting both 10/100/1000 Mbps speeds. This ensures that users can connect a variety of devices, ranging from office computers to network printers, all while maintaining optimal network performance. Additionally, the router supports both LAN and WAN interfaces, providing flexibility in deployment options.

Security is a crucial aspect of networking, and the Cisco 6901 does not disappoint in this regard. It comes equipped with advanced security features, including firewall capabilities, intrusion prevention, and VPN support. These features ensure that sensitive business data is protected from unauthorized access, while also providing secure remote access for employees.

Another essential characteristic of the Cisco 6901 is its support for various multimedia applications. The router comes with Quality of Service (QoS) features that prioritize voice, video, and data traffic, ensuring high-quality performance for applications such as VoIP and video conferencing. This is particularly valuable in today's business landscape, where effective communication is critical for success.

The Cisco 6901 is also designed for ease of management and configuration. It features a user-friendly interface that simplifies the setup process, along with comprehensive monitoring tools that enable administrators to keep an eye on network performance and address any issues proactively.

In summary, the Cisco Systems 6901 is a powerful, feature-rich router that combines advanced routing capabilities with robust security measures and multimedia support. Its flexibility, ease of management, and comprehensive service integration make it an excellent choice for businesses seeking to enhance their networking infrastructure. With the Cisco 6901, organizations can achieve efficient communication, secure data exchange, and high-performance network operations, positioning themselves well for future growth.
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