Cisco Unified Ip Phone Resets Unexpectedly; Verifying Physical Connection; Identifying Intermittent Network Outages - Cisco 7970G Administration Manual

Chapter 9 Troubleshooting and Maintenance

Cisco Unified IP Phone Resets Unexpectedly

Verifying Physical Connection

Identifying Intermittent Network Outages

Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones
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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
•
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.
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 Resets Unexpectedly
9-9