Yealink SIP-T38G

Getting Started
17
When the IP phones are simply plugged into the network, the DHCP process begins. The
IP phones broadcast DISCOVER messages to request the network information carried in
DHCP options and the DHCP server responds with the specific values in the
corresponding options.
The following table lists the common DHCP options supported by the 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 address 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
Servers
42
Specify a list of the NTP servers available to
the client by IP address.
Vendor-Specific
Information
43
Identify the vendor-specific information.
Vendor Class
Identifier
60
Identify the vendor type.
TFTP Server
Name
66
Identify a TFTP server when the 'sname' field
in the DHCP header has been used for DHCP
options.
Bootfile Name
67
Identify a bootfile when the 'file' field in the
DHCP header has been used for DHCP
options.