Chapter 3 Managing Cisco SIP IP Phones
Setting the Date, Time, and Daylight Savings Time
3-24
Cisco SIP IP Phone 7960 Administrator Guide
78-10497-02
Table 3-3 lists the actions that take place when a valid IP address is specified 
in the sntp_server parameter.
Table 3-3 Actions Based on sntp_mode When the sntp_server Parameter is Set to an IP Address
sntp_server
= 0.0.0.0
sntp_mode=
unicast
sntp_mode=
multicast
sntp_mode=
anycast
sntp_mode=
directedbroadcast
Sends
SNTP request to the 
SNTP server.
Nothing.
When in multicast 
mode, SNTP 
requests are not sent.
SNTP request to the 
SNTP server.
SNTP packet to the 
SNTP server.
After the first SNTP 
response is received, 
the phone switches 
to multicast mode.
Receives
SNTP response from 
the SNTP server and 
ignores responses 
from other SNTP 
servers.
SNTP data via the 
SNTP/NTP 
multicast address 
from the local 
network broadcast 
address.
SNTP response from 
the SNTP server and 
ignores responses 
from other SNTP 
servers.
SNTP data from the 
SNTP/NTP 
multicast address 
and the local 
network broadcast 
address and ignores 
responses from other 
SNTP servers.