Voice - Cisco Catalyst 2000 Configuration Handbook

Voice

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 nor-
■
mal Ethernet device is connected.
Inline power is provided over pairs 2 and 3 (RJ-45 pins 1,2 and 3,6) at 48V DC.
■
Inline power is available on a variety of Catalyst switch products.
■
Powered devices can connect to a wall power adapter and the power patch panel.
■
The devices use the patch panel as a backup power source.
Power is provided over pairs 1 and 4 (RJ-45 pins 4,5 and 7,8) at 48V DC.
■
A Catalyst switch can send instructions to a Cisco IP Phone on how to present
■
frames from its voice and data ports. This is done through Cisco Discovery Protocol
(CDP) messages.
Chapter 14