Cisco LAN Switching Configuration Handbook, Second Edition

Chapter 14Voice

See the following sections to configure and use these features:

• 14-1: Voice Ports: Covers the commands necessary to configure switched Ethernet ports for IP telephony

• 14-2: Voice QoS: Presents guidelines and configuration suggestions that provide end-to-end quality of service (QoS) in a campus network

14-1: Voice Ports

• Inline power is provided to a powered device as follows:

• A phantom-powered device can be detected as a switch port becomes active.

• A powered device loops the transmit and receives pairs back so that the switch detects its own 340 kHz test tone.

• Power is applied to the port if the device is present; no power is applied if a normal Ethernet device is connected.

• Inline power is provided over pairs 2 ...