Chapter 6 Troubleshooting and Maintenance
Troubleshooting ATA 187 Security
Checking Power Connection
In most cases, a phone will restart if it powers up by using external power but loses that connection and switches to PoE. Similarly, a phone may restart if it powers up by using PoE and then gets connected to an external power supply.
Troubleshooting ATA 187 Security
Table
Table
Problem
Possible Cause
CTL File Problems
Device authentication error. | CTL file does not have a |
| Cisco Unified Communications Manager |
| certificate or has an incorrect certificate. |
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Phone cannot authenticate CTL file. | The security token that signed the updated CTL |
| file does not exist in the CTL file on the phone. |
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Phone cannot authenticate any of the configuration | The configuration file may not be signed by the |
files other than ITL file. | corresponding certificate in the phone’s Trust List. |
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Phone does not register with | The CTL file does not contain the correct |
Cisco Unified Communications Manager. | information for the |
| Cisco Unified Communications Manager server. |
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Phone does not request signed configuration files. | The CTL file does not contain any TFTP entries |
| with certificates. |
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General Troubleshooting Tips
Table
Table
Summary | Explanation |
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Cisco does not support connecting a phone to another phone through | |
| the PC port. Each 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. |
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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 a phone and a mobile phone will have |
| poor voice quality. Use G.729 only when absolutely necessary. |
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Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.0
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