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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 55 Configuring a VoIP Network
Configuring VoIP on a Switch
High-Availability Support
To support high availability during a failover from the active supervisor engine to the standby supervisor
engine, the per-port power management and phone status information is synchronized between the active
and standby supervisor engines.
The information to be synchronized (on a per-port basis) is the presence of a phone, the phone power
status (on, off, denied, or faulty), allocated power, device class, device type, device maximum power,
and device discovery. The active supervisor engine sends this information to the standby supervisor
engine, and the standby supervisor engine updates its internal data structures. When a switchover occurs,
the standby supervisor engine allocates the power to the modules and ports from the available power,
one module at a time. Once the power for each module has been allocated, the supervisor engine
allocates the power to the phones, beginning with the lowest slot number, until all inline powered ports
have been either powered on, off, or denied.
Phone Detection Summary
Figure 55-4
shows how the system detects a phone that is connected to a Catalyst 6500 series switch port.
Figure 55-4
Power Detection Summary
Catalyst Switch
Switching module
Cisco phone
Wall-power
Supervisor engine discovers
the phone through CDP and/or
IEEE.
Third party phone
Switching module will not discover
the phone because CDP is not
supported. However, the supervisor
engine detects the phone and powers
it up.
without CDP.
or third party phone.
Phone is inserted but has not booted,
Network
Cisco phone
Wall-power
Supervisor engine discovers the
phone through CDP and/or IEEE.
or third party phone
device
with CDP.
10/100 module
10/100 module
10/100 module
10/100 module
10/100 module
discovers the phone.
then phone is removed. A network
device is plugged in. Inline power
might damage the network device.
Network
device
Cisco phone
38205
