General Troubleshooting Information - Cisco 8800 Series Administration Manual

Troubleshooting
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General Troubleshooting Information

The following table provides general troubleshooting information for the Cisco IP Phone.
Table 48: Cisco IP Phone troubleshooting
Summary
Connecting a Cisco IP Phone to
another Cisco IP Phone
Prolonged broadcast storms cause IP
phones to reset, or be unable to make
or answer a call
General Troubleshooting Information, page 289
Startup Problems, page 291
Phone Reset Problems, page 295
Phone Cannot Connect to LAN, page 297
Cisco IP Phone Security Problems, page 297
Video Call Problems, page 299
General Telephone Call Problems, page 300
Troubleshooting Procedures, page 301
Control Debug Information from Cisco Unified Communications Manager, page 305
Additional Troubleshooting Information, page 306
Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager
C H A P T E R
Explanation
Cisco does not support connecting an IP phone to another IP Phone
through the PC port. Each IP Phone should connect directly to a switch
port. If phones are connected together in a line by using the PC port,
the phones do not work.
A prolonged Layer 2 broadcast storm (lasting several minutes) on the
voice VLAN may cause IP phones to reset, lose an active call, or be
unable to initiate or answer a call. Phones may not come up until a
broadcast storm ends.
15
289