Printer FriendlyEmail Article Link

Spirent TestCenter: Why does the IEEE-1588v2 emulation send an Announce message with 35s offset?

Environment/Versions
  • v4.47
  • IEEE-1588v2 emulation
Answer
  • The OriginCurrentUTCOffset in the Announce packet is just to say which epoch time we are using. 
    • It’s in the 1588 spec, 7.2.3 page 42. 
  • Basically we are saying our clock is 35 seconds ahead of UTC time. 
    • This is a standard number which basically represents the number of leap seconds from PTP epoch (http://en.wikipedia.org/wiki/Leap_second). 
    • This value is hard coded and actually will change the June 2015 to 36.  This offset has no relation to local offset of the master clock that is received by the slave. 

Product : Spirent TestCenter,IEEE 1588