Components Of The Voip Wireless Network; Networking Protocols Used With Cisco Unified Wireless Ip Phones - Cisco 7921G - Unified Wireless IP Phone VoIP Administration Manual

Chapter 2 Overview of the VoIP Wireless Network
In dual band WLANs, it is possible to roam between 2.4 GHz bands (802.11b/g) and 5 GHz bands
Note
(802.11a). The phone moves out of range of one AP using one band and into the range of another that
has the same SSID but is using a different band. This can cause gaps in voice communications. To avoid
these communication gaps, try to use only one band for voice communications.
Related Topics
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Components of the VoIP Wireless Network

The wireless IP phone must interact with several network components in the WLAN to successfully
place and receive calls. The following topics describe network components:
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Networking Protocols Used with Cisco Unified Wireless IP Phones

Cisco Unified IP Phones support several networking protocols for voice communication.
describes the networking protocols that the Cisco Unified Wireless IP Phone 7921G supports.
Cisco Unified Wireless IP Phone 7921G Administration Guide for Cisco Unified Communications Manager Release 7.0
OL-15985-01
CCKM, a centralized key management protocol, provides a cache of session credentials on the
wireless domain server (WDS). As the phone roams from one AP to the next, CCKM compresses
the number of message exchanges during roaming by providing a master key stored on the WDS for
the AP to use. The reassociation exchange is reduced to two messages, thereby reducing the roaming
time.
For details about CCKM, refer to the "Cisco Fast Secure Roaming Application Note" at:
http://www.cisco.com/en/US/products/hw/wireless/ps4570/prod_technical_reference09186a00801
c5223.html
Voice QoS in a Wireless Network, page 2-10
Interacting with Cisco Unified Wireless APs, page 2-9
VoIP WLAN Configuration, page 2-18
Networking Protocols Used with Cisco Unified Wireless IP Phones, page 2-7
Interacting with Cisco Unified Wireless APs, page 2-9
Voice QoS in a Wireless Network, page 2-10
Interacting with Cisco Unified Communications Manager, page 2-12
Interacting with the DHCP Server, page 2-13
Components of the VoIP Wireless Network
Table 2-3
2-7