Yealink Yealink SIP-T48G, Administrator'S Manual, Page: 39 / 319

Getting Started
27
To configure static DNS when DHCP is used via phone user interface:
1. Press Menu->Settings->Advanced Settings (default password: admin)
->Network->DNS Server.
2. Press or , or the Switch soft key to select Enable from the Static DNS field.
3. Enter the desired values in the Pri DNS and Sec DNS fields respectively.
4. Press the Save soft key to accept the change.
The IP phone reboots automatically to make settings effective after a period of time.
DHCP provides a framework for passing information to TCP/IP network devices. Network
and other control information are carried in tagged data items that are stored in the
options field of the DHCP message. The data items themselves are also called options.
DHCP can be initiated by simply connecting the IP phone with the network. IP phones
broadcast DISCOVER messages to request the network information carried in DHCP
options, and the DHCP server responds with specific values in corresponding options.
The following table lists common DHCP options supported by IP phones.
Parameter DHCP Option Description
Subnet Mask 1 Specify the client’s subnet mask.
Time Offset 2
Specify the offset of the client's subnet in
seconds from Coordinated Universal Time
(UTC).
Router 3
Specify a list of IP addresses for routers on
the client’s subnet.
Time Server 4
Specify a list of time servers available to
the client.
Domain Name
Server
6
Specify a list of domain name servers
available to the client.
Log Server 7
Specify a list of MIT-LCS UDP servers
available to the client.
Host Name 12 Specify the name of the client.
Domain Server 15
Specify the domain name that client should
use when resolving hostnames via DNS.
Broadcast
Address
28
Specify the broadcast address in use on
the client's subnet.
Network Time
Protocol
42
Specify a list of NTP servers available to the