Yealink SIP-T2 Series Administrator's Manual page 22

Administrator's Guide for SIP-T23 & T23P & T23G IP Phones
The initialization process of the IP phone is responsible for network connectivity and
operation of the IP phone in your local network.
Once you connect your IP phone to the network and to an electrical supply, the IP phone
begins its initialization process.
During the initialization process, the following events take place:
Loading the ROM file
The ROM file resides in the flash memory of the IP phone. The IP phone comes from the
factory with a ROM file preloaded. During initialization, the IP phone runs a bootstrap
loader that loads and executes the ROM file.
Configuring the VLAN
If the IP phone is connected to a switch, the switch notifies the IP phone of the VLAN
information defined on the switch (if using LLDP or CDP). The IP phone can then proceed
with the DHCP request for its network settings (if using DHCP).
Querying the DHCP (Dynamic Host Configuration Protocol) Server
The IP phone is capable of querying a DHCP server. DHCP is enabled on the IP phone
by default. The following network parameters can be obtained from the DHCP server
during initialization:
IP Address

Subnet Mask

Gateway

Primary DNS (Domain Name Server)

Secondary DNS

You need to configure network parameters of the IP phone manually if any of them is not
supplied by the DHCP server. For more information on configuring network parameters
manually, refer to
Contacting the provisioning server
If the IP phone is configured to obtain configurations from the provisioning server, it will
connect to the provisioning server and download the configuration file(s) during startup.
The IP phone will be able to resolve and update configurations written in the
configuration file(s). If the IP phone does not obtain configurations from the provisioning
server, the IP phone will use configurations stored in the flash memory.
Updating firmware
If the access URL of firmware is defined in the configuration file, the IP phone will
download firmware from the provisioning server. If the MD5 value of the downloaded
10
Configuring Network Parameters Manually on page 24.