What is the frequency of the time synchronization between a Sarix camera and a time server?

Issue

Need to know what will be the load on the network added by the time synchronization.

Product Line

Pelco Cameras

Environment

  • Sarix camera
  • NTP server
  • Low bandwidth network connection

Cause

The available bandwidth is low on the network connection between the camera and the time server.

Resolution

The way NTP works is it first gets a time value from the NTP server to do an initial time set on the camera.  Then it polls the time server periodically to see how the internal clock compares to the time server.  Initially, these queries are somewhat frequent (minimum poll time is 6 seconds).  However, once the code figures out what the “drift” is from the camera's clock to the server's clock (for over-simplification, say the camera loses one second every minute, or the camera says it has been 59 seconds when the server says it has been a minute), it decreases the frequency of the polls to one every 60 seconds (or so) and if that stays pretty consistent (depends on how consistent the camera clock is) it decreases even more to like one poll every 4000 seconds. Maximum poll time is 129 600 seconds (1.5 days).

To sums it up, NTP will not create much additional load at all to the network.