Cisco 7920 - Unified Wireless IP Phone VoIP Administration Manual page 46

Components of the VoIP Wireless Network
Voice Quality in a Wireless Network
Cisco Wireless IP Phone 7920 Administration Guide for Cisco CallManager Release 4.0 and 4.1
2-12
Interacting with the Cisco Aironet Access Point, page 2-8
•
Wireless Network and Access Point Configuration, page 2-19
•
Voice traffic on the Wireless LAN, like data traffic, is susceptible to delay, jitter,
and packet loss. These issues do not impact the data end user, but have serious
implications for a voice call. To ensure that voice traffic receives timely and
reliable treatment with low delay and low jitter, you must use Quality of Service
(QoS), and use separate virtual LANs (VLANs) for voice and data. By isolating
the voice traffic onto a separate VLAN, you can use QoS to provide priority
treatment for voice packets when traveling across the network. You need the
following VLANs on the network switches and the access points that support
voice connections on the WLAN.
• Voice VLAN—Voice traffic to and from the wireless IP phone
Native VLAN—Data traffic to and from the wireless PC (native VLAN)
•
Assign separate SSIDs to the voice and to the data VLANs. You can also
configure a separate management VLAN in the WLAN, but do not associate an
SSID with the management VLAN.
By separating the phones onto a voice VLAN and marking voice packets with
higher CoS, you can ensure that voice traffic gets priority treatment over data
traffic.You can management traffic resulting in lower delay and fewer lost
packets.
For more information, refer to the Cisco Wireless IP Phone 7920 Design and
Deployment Guide.
Related Topics
Security Mechanisms in the Wireless Network, page 2-13
•
Interacting with Cisco CallManager, page 2-17
•
Wireless Network and Access Point Configuration, page 2-19
•
Chapter 2 An Overview of the Wireless Network
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