Cisco Systems OL-8978-02 manual Phone Detection Summary, High-Availability Support, 55-16

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 55-4shows how the system detects a phone that is connected to a Catalyst 6500 series switch port.

Figure 55-4 Power Detection Summary

Catalyst Switch

10/100 module

Cisco phone	Switching module
	discovers the phone.

10/100 module

Cisco phone	Supervisor engine discovers
or third party phone.	the phone through CDP and/or
	IEEE.

Wall-power

10/100 module

10/100 module

Third party phone without CDP.

Network

device

Switching module will not discover the phone because CDP is not supported. However, the supervisor engine detects the phone and powers it up.

Phone is inserted but has not booted, then phone is removed. A network device is plugged in. Inline power might damage the network device.

		Cisco phone
	Network
10/100 module
		or third party phone
	device
		with CDP.
		Wall-power

Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7

55-16

Supervisor engine discovers the phone through CDP and/or IEEE.

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