Yealink SIP-T19 E2 T4 Series, Administrator'S Manual

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Administrator’s Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series IP Phones
12
A dialog box pops up to prompt that the settings will take effect after a reboot.
6.
Press
OK
to reboot the phone.
DHCP Option
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.
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.
Network Time
Protocol Servers
42
Specify a list of 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.
For more information on DHCP options, refer to RFC 2131 or RFC 2132 .
If you do not have the ability to configure the DHCP options for discovering the provisioning
server on the DHCP server, an alternate method of automatically discovering the provisioning