NetRunner WAN User’s Manual
Startup
3-10
Real Time Clock
Administrative Functions
The Real Time Clock device allows you to set and control timespecific events
for the entire network using one clock. This has the advantage of not needing
to interpret multiple time zones for specific events. Call accounting records
can have one system time for better assessment and evaluation.
The Real Time Clock system works in conjunction with other valuable
timerelated features such as Bandwidth on Demand. The Real Time Clock
allows setting secondary and primary link operations during specific hours on
specific days of the week. For example, you can schedule a time when a link
can be brought up or shut down. (Bandwidth on Demand features are
described on page 49.)
Characteristics
D
The clock source maintains network time automatically by
broadcasting Time message every two minutes.
D
Every unit (with or without a Real Time Clock device) in the network
sets its clock to the specified time.
D
A hierarchy of units containing Real Time Clocks is determined by the
unit's node number. The unit with the lowest node number is the
network time master.
D
Other sites may also have real time clocks, and the unit with the next
lowest node number assumes control in the event that the master
fails.
Network Time Master
The unit with the lowest node number in the network and which has a Real
Time Clock is the network time master. This unit broadcasts its time to the
entire network at twominute intervals. A Time broadcast includes Time,
Date, and Day of the Week settings.
Any units featuring Real Time Clocks provide network time redundancy.
9
12
10
11
13
Node 9 is the network
time master.
Real Time Clock
Unit
Release 5.
x
Real Time Clock
Unit
Release 5.
x
