Networking Forum

1588v2 Packet Format

  Satheesh Kumar S        04/Feb/2015

In this section we mainly discuss the following three 1588v2 packet formats



a. PTP over UDP over IPv4 over Ethernet



b. PTP over UDP over IPv6 over Ethernet



c. PTP over IEEE802.3 Ethernet



Following diagram represents the packet format with different layer of encapsulation.





It is evident from the below snippet that PTP message length is not same for different messages. The suffix filed is optional and it may have zero length. The message length starts with 1st octet of PTP header & ends with last octet of suffix if any.



Sample captures for PTP over IEEE802.3 are shown below.



Sync Message





Delay-Request Message





Delay-Response Message





Announce Message





For more details refer the IEEE standards specified in the Reference Section.


ANNAND RODRIGUES  : Thanks for the packet captuer...it explains all the field of the PTP header. Can you please explain the below 1. 802.1as conform: false2. Flags would this be updated in case of unicast and 2 step mode.3. control: i though this was for backward compactability for v1

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venu  : Do we have the ITU-T G.8273.3 spec for Transparent clock support?

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References

IEEE 1588-2008 Standard