Specifications
Table Of Contents
- Cisco Unified Wireless IP Phone 7921G Administration Guide for Cisco Unified CallManager Release 4.1, 4.2, 5.0 and Later
- Contents
- Preface
- An Overview of the Cisco Unified Wireless IP Phone 7921G
- An Overview of the Voice Over IP Wireless Network
- Understanding the Wireless LAN
- Components of the VoIP Wireless Network
- Voice Over IP Wireless Network Configuration
- Site Survey Verification
- Setting Up the Cisco Unified Wireless IP Phone 7921G
- Before You Begin
- Installing the Cisco Unified Wireless IP Phone 7921G
- Powering On the Cisco Unified Wireless IP Phone 7921G
- Understanding the Phone Startup Process
- Using the Cisco Unified Wireless IP Phone 7921G Web Pages
- Using the USB Connection for Initial Phone Configuration
- Updating Phones Remotely
- Configuring Network Profiles
- Configuring USB Settings
- Configuring Trace Settings
- Using System Settings
- Configuring Settings on the Cisco Unified Wireless IP Phone 7921G
- Accessing Network and Phone Settings
- Configuring Network Profile Settings
- Changing Phone Settings
- Configuring the Security Certificate on the Phone
- Changing the USB Configuration
- Configuring Features, Templates, Services, and Users
- Configuring Cisco Unified Wireless IP Phones in Cisco Unified CallManager
- Telephony Features Available for the Phone
- Specific Configuration Options for the Cisco Unified Wireless IP Phone 7921G
- Configuring Softkey Templates
- Modifying Phone Button Templates
- Setting Up Services
- Configuring Corporate and Personal Directories
- Adding Users to Cisco Unified CallManager
- Managing the User Options Web Pages
- Creating Custom Phone Rings
- Viewing Security, Device, Model, and Status Information on the Phone
- Monitoring the Cisco Unified Wireless IP Phone Remotely
- Troubleshooting the Cisco Unified Wireless IP Phone 7921G
- Resolving Startup and Connectivity Problems
- Resolving Voice Quality and Roaming Problems
- General Troubleshooting Information
- Erasing the Local Configuration
- Providing Information to Users By Using a Website
- Supporting International Users
- Physical and Operating Environment Specifications
- Checklist for Deploying the Cisco Unified Wireless IP Phone 7921G
- Index
9-17
Cisco Unified Wireless IP Phone 7921G Administration Guide for Cisco Unified CallManager Release 4.1, 4.2, 5.0
OL-10802-02
Chapter 9 Troubleshooting the Cisco Unified Wireless IP Phone 7921G
Resolving Voice Quality and Roaming Problems
• If using EAP-FAST, LEAP, or Auto (AKM) authentication, the access point
might be using filters to block TCP ports. The ACS server uses port 1645 for
authentication and 1646 for accounting and the RADIUS server uses port
1812 for authentication and 1813 for accounting.
Related Topics
• Resolving Startup and Connectivity Problems, page 9-1
• Resolving Voice Quality and Roaming Problems, page 9-11
• General Troubleshooting Information, page 9-20
• Monitoring the Voice Quality of Calls, page 9-17
Monitoring the Voice Quality of Calls
To measure the voice quality of calls that are sent and received within the network,
Cisco
Unified IP Phones use these statistical metrics that are based on
concealment events. The DSP plays concealment frames to mask frame loss in the
voice packet stream.
• Concealment Ratio metrics—Show the ratio of concealment frames over total
speech frames. An interval conceal ratio is calculated every 3 seconds.
• Concealed Second metrics—Show the number of seconds in which the DSP
plays concealment frames due to lost frames. A severely “concealed second”
is a second in which the DSP plays more than five percent concealment
frames.
• MOS-LQK metrics—Use a numeric score to estimate the relative voice
listening quality. The Cisco
Unified IP Phone calculates the mean opinion
score (MOS) for listening quality (LQK) based audible concealment events
due to frame loss in the preceding 8 seconds, and includes perceptual
weighting factors such as codec type and frame size.
MOS LQK scores are produced by a Cisco proprietary algorithm, Cisco Voice
Transmission Quality (CVTQ) index. Depending on the MOS LQK version
number, these scores might be compliant with the International
Telecommunications Union (ITU) standard P.564. This standard defines
evaluation methods and performance accuracy targets that predict listening
quality scores based on observation of actual network impairment.