Installation Manual for digital sets - IP sets - SIP sets
AMT/PTD/TR/0001/3/7/EN
SIP PHONES 51i, 53i, 55i AND 57i
05/2008
Page
9-39
9.12.5
NTP server
Time is set on the phones via an NTP server. The NTP server IP address must be configured in the
general parameters (the file aastra.cfg) or specific parameters (file @MAC.cfg) of the SIP phones.
Example of NTP server: Absolute Time Server 2.2
The server proposes by default UDP and TCP ports 37 and SNTP port 123. These ports may be
redefined by the user. The SIP phone uses SNTP port 123.