Cisco 7921G Administration Guide - Page 41

Chapter 2 Overview of the VoIP Wireless Network Components of the VoIP Wireless Network 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 3-18 Interacting with the DHCP Server Dynamic Host Configuration Protocol (DHCP) is a communications protocol that enables network administrators to manage and automate the assignment of 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. If DHCP is enabled in the network, the Cisco Unified Wireless IP Phone 7921G uses the DHCP scope settings in the DHCP server to perform the phone provisioning bootup process. You must configure the settings of the DHCP server in the Cisco Unified Communications Manager network. The DHCP scope settings include the following: • TFTP servers • DNS server IP address (optional unless using host names) • Pool and range of the subnet mask, IP address, and gateway The priority of the DHCP settings for the TFTP server is unique to the Cisco Unified Wireless IP Phone 7921G, as shown in Table 2-4. Table 2-4 Priority 1st 2nd 3rd 4th DHCP Settings Priority DHCP Settings DHCP option 150 DHCP option 66 SIADDR ciscoCM1 If DHCP is disabled, the Cisco Unified Wireless IP Phone 7921G uses the following network settings in Table 2-5 to perform the phone provisioning bootup process. You must configure these static parameters for each Cisco Unified Wireless IP Phone 7921G. Table 2-5 Static IP Addresses When DHCP is Disabled Static Setting IP Address Subnet Mask Default Router 1 Description IP address, the unique identifier assigned by the system administrator for the phone. Used to partition the IP address into a network identifier and host identifier so TCP/IP can distinguish between them. Identifies the gateway that provides connectivity to the IP network beyond the subnet to which the phone belongs. OL-15985-01 Cisco Unified Wireless IP Phone 7921G Administration Guide for Cisco Unified Communications Manager Release 7.0 2-13