Symptom: Cisco Unified Ip Phone Unable To Obtain Ip Address; Cisco Unified Ip Phone Resets Unexpectedly - Cisco CP-3911 - Unified SIP Phone 3911 VoIP Administration Manual

Cisco Unified IP Phone Resets Unexpectedly

Symptom: Cisco Unified IP Phone Unable to Obtain IP Address

Cisco Unified IP Phone Resets Unexpectedly
Cisco Unified SIP Phone 3911 Administration Guide for Cisco Unified Communications Manager
7-8
the phone in the Cisco Unified Communications Manager database, but there
is no button on the phone with which calls can be answered. These directory
numbers should be removed from the phone and deleted if necessary.
If a phone is unable to obtain an IP address when it starts up, the phone may not
be on the same network or VLAN as the DHCP server, or the switch port to which
the phone is connected may be disabled.
Make sure that the network or VLAN to which the phone is connected has access
to the DHCP server, and make sure that the switch port is enabled.
If users report that their phones are resetting during calls or while idle on their
desk, you should investigate the cause. If the network connection and Cisco
Unified Communications Manager connection are stable, a Cisco Unified IP
Phone should not reset on its own.
Typically, a phone resets if it has problems connecting to the Ethernet network or
to Cisco Unified Communications Manager. These sections can help you identify
the cause of a phone resetting in your network:
Verifying Physical Connection, page 7-9
•
Identifying Intermittent Network Outages, page 7-9
•
Verifying DHCP Settings, page 7-9
•
Checking Static IP Address Settings, page 7-10
•
Verifying Voice VLAN Configuration, page 7-10
•
Verifying that the Phones Have Not Been Intentionally Reset, page 7-10
•
Eliminating DNS or Other Connectivity Errors, page 7-11
•
Chapter 7 Troubleshooting and Maintenance
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