Cisco Systems 7970G Cisco Unified IP Phone Resets Unexpectedly

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Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones

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Chapter9 Troubleshooting and Maintenance

Cisco Unified IP Phone Resets Unexpectedly

Cisco Unified IP Phone Resets Unexpectedly

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 CiscoUnified IP Phone

should not reset on its own.

Typically, a phone resets if it has problems connecting to the Ethernet network or

to Cisco UnifiedCallManager. These sections can help you identify the cause of

a phone resetting in your network:

•Verifying Physical Connection, page9-9

•Identifying Intermittent Network Outages, page9-9

•Verifying DHCP Settings, page9-10

•Checking Static IP Address Settings, page 9-10

•Verifying Voice VLAN Configuration, page9-10

•Verifying that the Phones Have Not Been Intentionally Reset, page9-11

•Eliminating DNS or Other Connectivity Errors, page9-11

•Checking Power Connection, page9-12

Verify that the Ethernet connection to which the CiscoUnified IP Phone is

connected is up. For example, check if the particular port or switch to which the

phone is connected is down and that the switch is not rebooting. Also make sure

that there are no cable breaks.

Intermittent network outages affect data and voice traffic differently. Your

network might have been experiencing intermittent outages without detection. If

so, data traffic can resend lost packets and verify that packets are received and

transmitted. However, voice traffic cannot recapture lost packets. Rather than

retransmitting a lost network connection, the phone resets and attempts to

reconnect its network connection.