Cisco Systems 7970G Cisco Unified IP Phone Resets Unexpectedly, Verifying Physical Connection

Chapter 9 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 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 9-9

•Identifying Intermittent Network Outages, page 9-9

•Verifying DHCP Settings, page 9-10

•Checking Static IP Address Settings, page 9-10

•Verifying Voice VLAN Configuration, page 9-10

•Verifying that the Phones Have Not Been Intentionally Reset, page 9-11

•Eliminating DNS or Other Connectivity Errors, page 9-11

•Checking Power Connection, page 9-12

Verifying Physical Connection

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 and that the switch is not rebooting. Also make sure that there are no cable breaks.

Identifying Intermittent Network Outages

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.

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

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