Symptom: Cisco Unified Ip Phone Unable To Obtain Ip Address; Cisco Unified Ip Phone Resets Unexpectedly; Verifying Physical Connection - Cisco 3951 Administration Manual

Cisco Unified IP Phone Resets Unexpectedly

Symptom: Cisco Unified IP Phone Unable to Obtain IP Address

Cisco Unified IP Phone Resets Unexpectedly

Verifying Physical Connection

Cisco Unified SIP Phone 3951 Administration Guide for Cisco Unified CallManager 5.1
7-8
If a phone is unable to obtain an IP address when it starts up, the phone may be
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 CallManager 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 CallManager. These sections can help you identify the cause of
a phone resetting in your network:
• Verifying Physical Connection, page 7-8
Identifying Intermittent Network Outages, page 7-9
•
Verifying DHCP Settings, page 7-9
•
Checking Static IP Address Settings, page 7-9
•
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
•
Verify that the Ethernet connection to which the Cisco Unified IP Phone is
connected is up. For example, check if the particular port or switch to which the
phone is connected is down.
Chapter 7 Troubleshooting and Maintenance
OL-10969-01