Cisco 7821 Administration Manual page 27

• Data traffic present on the VLAN supporting phones might reduce the quality of VoIP traffic.
• Network security may indicate a need to isolate the VLAN voice traffic from the VLAN data traffic.
You can resolve these issues by isolating the voice traffic onto a separate VLAN. The switch port to which
the phone connects would be configured for separate VLANs for carrying:
• Voice traffic to and from the IP phone (auxiliary VLAN on the Cisco Catalyst 6000 series, for example)
• Data traffic to and from the PC that connects to the switch through the computer (access) port of the IP
Isolating the phones on a separate, auxiliary VLAN increases the quality of the voice traffic and allows a large
number of phones to be added to an existing network that does not have enough IP addresses for each phone.
For more information, see the documentation that is included with a Cisco switch. You can also access switch
information at this URL:
http://cisco.com/en/US/products/hw/switches/index.html
Cisco Unified Communications Manager Interaction
Cisco Unified Communications Manager is an open, industry-standard call processing system. Cisco Unified
Communications Manager software sets up and tears down calls between phones, integrating traditional PBX
functionality with the corporate IP network. Cisco Unified Communications Manager manages the components
of the IP telephony system, such as the phones, the access gateways, and the resources necessary for features
such as call conferencing and route planning. Cisco Unified Communications Manager also provides:
• Firmware for phones
• Certificate Trust List (CTL) and Identity Trust List (ITL) files using the TFTP service
• Phone registration
• Call preservation, so that a media session continues if signaling is lost between the primary
For information about configuring Cisco Unified Communications Manager to work with the IP phones
described in this chapter, see the "Cisco IP Phone Configuration" chapter in the Cisco Communications
Manager Administration Guide.
Note If the Cisco IP Phone model that you want to configure does not appear in the Phone Type drop-down list
in Cisco Unified Communications Manager Administration, install the latest support patch for your version
of Cisco Unified Communications Manager from Cisco.com.
Cisco Unified Communications Manager Express Interaction
When the Cisco IP Phone works with the Cisco Unified Communications Manager Express, the phones must
go into CME mode.
When a user invokes the conference feature, the tag allows the phone to use either a local or network hardware
conference bridge.
phone (native VLAN)
Communications Manager and a phone
Cisco IP Phone 7821, 7841, and 7861 Administration Guide for Cisco Unified Communications Manager 10.0 (SIP)
Cisco Unified Communications Manager Interaction
13