Cisco Catalyst Switches

This chapter covers the following topics:

• Identifying the functions that Cisco Catalyst switches perform in a Cisco IP telephony solution
• The three options for powering Cisco IP Phones
• The two types of PoE that Cisco Catalyst switches provide and the Cisco Catalyst switches that support PoE
• Identifying the commands to configure PoE on Cisco Catalyst switches
• Configuring dual VLANs on a single port on a Cisco Catalyst switch so that the IP Phones reside in a separate VLAN
• Configuring CoS on Cisco Catalyst switches so that voice traffic has priority over data traffic as it travels throughout the network

Deploying IP telephony requires planning how you will power the IP Phones and how the voice network traffic will mix with the data network while ensuring that the data traffic does not degrade the quality of the voice calls.

Cisco Catalyst switches provide three features that aid an IP telephony deployment: inline power, voice VLANs, and class of service (CoS). Using the Cisco Catalyst switch to power IP Phones can save on wiring costs and simplifies management. Enabling multiple VLANs in a single port and placing voice packets in one VLAN and data in another VLAN saves money by reducing the number of switch ports. Extending CoS to the IP Phone improves voice quality by ensuring that voice packets receive priority over data.

This lesson discusses the three major functions that Cisco Catalyst switches perform in an IP telephony network and describes how to configure a Cisco Catalyst switch to enable these functions.