Specifications

Table Of Contents
2-25
Cisco Unified Wireless IP Phone 7921G Administration Guide for Cisco Unified CallManager Release 4.1, 4.2, 5.0
OL-10802-02
Chapter 2 An Overview of the Voice Over IP Wireless Network
Components of the VoIP Wireless Network
Related Topics
Configuring the Cisco Unified Wireless IP Phone 7921G in Cisco Unified
CallManager, page 1-17
Phone Configuration Files and Profile Files, page 2-25
Phone Configuration Files and Profile Files
Configuration files for a phone define parameters for connecting to Cisco
Unified
CallManager and are stored on the TFTP server. In general, any time you
make a change in Cisco Unified
CallManager Administration that requires
resetting the phone, the phone configuration file changes automatically.
Configuration files also contain information about the correct image load for the
phone. If this image load differs from the one currently loaded on a phone, the
phone contacts the TFTP server to request the new image file.
The phone first requests the configuration file SEPxxxxxxxxxxxx.cnf.xml, where
each xx is the two-digit lowercase hexadecimal representation of each integer in
the phone’s MAC address. If the phone cannot find this file, it requests the
configuration file XMLDefault.cnf.xml.
After the phone obtains the *.cnf.xml files, it requests a phone-specific profile
file. If a phone cannot find this profile file, it requests the appropriate common
profile file.
After the phone finds one of the profile files, or if it cannot find a profile file, it
continues with its startup process.
Related Topic
Understanding the Phone Startup Process, page 3-26
Interacting with the DHCP Server
Dynamic Host Configuration Protocol (DHCP) is a communications protocol that
lets network administrators manage and automate the assignment of Internet
Protocol (IP) addresses in a network. When an IP device is added to the network,
it must have a unique IP address. Without DHCP, the IP address must be entered
manually at each device. DHCP allocates IP addresses dynamically and reuses IP
addresses when devices no longer need them.