Cisco Systems OL-23092-01 manual Understanding the Phone Startup Process, Purpose Related Topics

Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network

Understanding the Phone Startup Process

Understanding the Phone Startup Process

When connecting to the VoIP network, the Cisco Unified IP Phone goes through a standard startup process, as described in Table 2-4. Depending on your specific network configuration, not all of these process steps may occur on your Cisco Unified IP Phone.

Table 2-4	Cisco Unified IP Phone Startup Process
Task	Purpose	Related Topics
1.	Obtaining Power from the Switch.	See Providing Power to the Phone, page 2-4.
	If a phone is not using external power, the switch provides	See Resolving Startup Problems, page 9-1.
	in-line power through the Ethernet cable that is attached to
	the phone.
2.	Loading the StoredPhone Image.	See Resolving Startup Problems, page 9-1.
	The Cisco Unified IP Phone has non-volatile flash memory
	in which it stores firmware images and user-defined
	preferences. At startup, the phone runs a bootstrap loader
	that loads a phone image stored in flash memory. Using this
	image, the phone initializes its software and hardware.
3.	Configuring VLAN.	See Network Configuration Menu, page 4-5.
	If the Cisco Unified IP Phone is connected to a Cisco	See Resolving Startup Problems, page 9-1.
	switch, the switch next informs the phone of the voice
	VLAN defined on the switch port. The phone needs to
	know its VLAN membership before it can proceed with the
	Dynamic Host Configuration Protocol (DHCP) request for
	an IP address.
4.	Obtaining an IP Address.	See Network Configuration Menu, page 4-5.
	If the Cisco Unified IP Phone is using DHCP to obtain an	See Resolving Startup Problems, page 9-1.
	IP address, the phone queries the DHCP server to obtain
	one. If you are not using DHCP in your network, you must
	assign static IP addresses to each phone locally.
5.	Accessing a TFTP Server.	See Network Configuration Menu, page 4-5.
	In addition to assigning an IP address, the DHCP server	See Resolving Startup Problems, page 9-1.
	directs the Cisco Unified IP Phone to a TFTP server. If the
	phone has a statically defined IP address, you must
	configure the TFTP server locally on the phone. The phone
	then contacts the TFTP server directly.
	Note You can also assign an alternative TFTP server to
	use instead of the one assigned by DHCP.
6.	Requesting the CTL file.	Refer to Cisco Unified Communications Manager
	The TFTP server stores the CTL file. This file contains the	Security Guide, Configuring the Cisco CTL
	certificates necessary for establishing a secure connection	Client.
	between the phone and Cisco Unified Communications
	Manager.

Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5

OL-23092-01 2-9