Chapter 15: IP Phone Installation Associating a User Group with Unassigned IP Phones
ShoreTel 8 Planning and Installation Guide 211
For help on configuring these DHCP Options, see Section 9.7 on page 113.
18.104.22.168 SNTP Server
The DHCP server should be configured to provided the address of your network’s SNTP
server to provide date and time information to the IP phones.
22.214.171.124 GMT Offset
The DHCP server must provide the telephones with the appropriate Greenwich Mean Time
(GMT) offset to adjust the provided network time for the time zone of the telephone’s
location. When a single DHCP server is used for IP phones in multiple sites, the DHCP
server must be configured to provide the correct GMT offset for the different sites based on
the location or subnet where the telephone that issues the DHCP request is located.
When using the Microsoft DHCP server, you must enter the time offset that is provided to
the IP phones in hex (hexadecimal) if the offset is negative. If you enter a negative number
in decimal, the DHCP server software modifies the entry to be the positive number of the
same magnitude or the absolute value before storing the value in hex. For example, if the
desired offset is -8 hours or -28800 seconds, you enter the hex value of 0xFFFF8F80.
•-8 hr = 0xFFFF8F80
•-7 hr = 0xFFFF9D90
•-6 hr = 0xFFFFABA0
•-5 hr = 0xFFFFB9B0
15.4 Associating a User Group with Unassigned IP
Unassigned IP phones are available for users configured for Any IP Phone. Select the user
group that will have access to unassigned IP phones from the pull-down list.
Since unassigned IP phones are not associated with a user, you cannot report on calls made
from these telephones and associate them with an individual user. It is recommended that
unassigned IP phones be configured with a class of service with minimal calling privileges.