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Spirent TestCenter: How can we set the rate at which the PTP packets can be sent?

Environment/Versions
  • Spirent TestCenter
Answer
  • The maximum rate at which PTP packets can be sent is 128pps.
  • 1588 uses a Logarithmic scale for setting rate for all messages. The fields to change interval or rate highlighted listed below

  • For example above:
    • Announce message rate is 2 ^0 = 1pps
    • Sync rate is 2 ^-4 = 16pps
    • Delay request rate= 16pps
  • In order to get packet rates of 128pps set the log interval = -7
    • Basically its 2 to the power of n, where n = the interval value entered in those fields
    • What is the frame rate for values -4 and +4?
      • -4 = 1/(2^4) = 0.0625s interval (this means 16 packets per second)
      • +4 = 2^4 = 16s interval (this means 1 packet every 16 seconds)
    • What is the frame rate for values -128 and +127?
      • -128 = 1/(2^128) interval in seconds
      • +127 = 2^127 interval in seconds
  • If you need to do a large number of slaves at high rates use Scale Mode=GenTx, in this mode there are no clock statistics since the rates are very high

 

 


Product : Spirent TestCenter,Spirent TestCenter,IEEE 1588