plugfest We have all read IEEE 1588-2008 and associated profiles, and tried to implement them faithfully. But how can we know that our team interpreted the standards the same as engineers from other organizations? There are two things which you can do to verify that you have a good implementation of PTP:

  • 1. Have your PTP implementation tested at a conformance certification laboratory. They will submit your device to a battery of standard tests designed to prove correct protocol behavior. They will also capture the data and identify any issues.

  • 2. Participate in plugfests. At a plugfest, equipment from many vendors is brought together to identify interoperability issues. Even devices which have been certified by the same conformance certification lab may not fully interoperate. How can that be? Certification laboratories don't tell you what happens when devices choose different subsets of optional features. They don't tell you what common incompatible configurations will look like in a live network. The labs may even be missing a key test, which will be revealed in a plugfest. For example, does your device behave in a robust manner when other devices are acting incorrectly?

It is recommended that developers take prototypes to both certification labs and plugfests. Because the ISPCS is only a week-long event, in a different location each year, it is not possible to set up a complete certification laboratory as part of the event. However, the ISPCS does include a three-day Plugfest for interoperability testing.

The Plugfest takes place October 11-13, 2015 and provides an opportunity to test and demonstrate device and system interoperability and resolve compatibility issues. Implementers are invited and encouraged to cooperate with others to demonstrate system-wide clock synchronization and operation of protocols across as wide a spectrum of devices as possible.

Added benefits for plugfest attendees on ISPCS 2015

  • PAL (Experiment and Verification Center, State Grid Electric Power Research Institute), one of SGCC's test and inspection laboratories providing authoritative tests required for deployment in Chinese power grids, will participate in ISPCS 2015 as Technical Co-host. During ISPCS 2015:
    • PAL will take part in the plugfest, showcasing its rich testing and deployment experience with IEEE 1588.
    • PAL will provide a test environment in which all plugfest attendees can perform free testing with their equipment under Chinese power grid technical standards and requirements.
    This will provide attendees a good opportunity to understand the Chinese power grid standards and requirements for IEEE 1588 equipment.
    Here is the PAL Test Service Menu.

  • UNH-IOL (University of New Hampshire InterOperability Laboratory), internationally authoritative test lab for IEEE 1588, will also participate in ISPCS 2015 as Technical Co-host. The IOL will provide all plugfest attendees:
    • Free partial execution of an IOL test plan during the plugfest. The growing set of test plans can be found here.
    • Official sample report for an IOL test plan, based on the above testing
    • IOL software demonstration
    • IOL software 30-day trial license
    The participation of the IOL will give plugfest participants the chance to have their equipment tested with the internationally authoritative test lab. This is especially helpful for those companies wishing to enter the global market.

  • Important end users will be invited to attend Industry Day (Oct 14), during which successful tests from the Plugfest will be demonstrated. Detailed introductions of the plugfest tests, plus specially arranged seminars hosted by Platinum and Gold sponsors, will help end users and other industry day attendees to understand the application of IEEE 1588. Industry Day will provide plugfest attendees an opportunity to display their products and technologies in front of global end users.

  • Plugfest attendees will have the option to request from the ISPCS plugfest committee a formal test report regarding their participation in ISPCS 2015. Here is an example of the plugfest test report. Also, plugfest attendees will have the opportunity to list their devices on the ISPCS Plugfest Tested Devices webpage.


Prospective Plugfest participants must fill out the Plugfest Registration Form and email the completed form to about their intention to participate. While the Plugfest Registration Form is submitted, a Plugfest Wiki account will be provided for the access to Plugfest Wiki: where you can find further information about Plugfest.

Please note that each Plugfest participant must register for the main conference.


Plugfest participants will want to attend one of the two planning teleconferences prior to the event, where they can ask questions and make suggestions. Registered participants will be notified of the teleconferences by the Plugfest committee.

Profiles to be tested at this year's Plugfest are:

1. Default Profile

Network topology: chain of transparent clocks (TCs) and boundary clocks (BCs). Ordinary clocks (OCs) will be included upon request. Two networks: layer-2 peer-to-peer (L2 P2P) and layer-3 end-to-end (L3 E2E).

  • Set up
  • Rogue master test
  • Leap second
  • Connect Default networks together by BC
  • Intermittent GPS availability

2. C37.238-2011

Network topology: ring of TCs. BCs hand off to TCs. OCs included upon request.

  • Set-up
  • Basic interoperability, cycle through grandmasters (GMs) by changing priority 1 fields
  • Rogue master test
  • Injection of default profile GM
  • Injection of C37.238-revision GM
  • Traffic flooding tests (non-PTP traffic)
  • Leap second

3. G.8265

Network topology: line of Gigabit routers/switches

  • Set-up
  • Basic interoperability, GM IP addresses to be posted
  • Simulation of busy networks added in series with GMs (provided by test vendors)
  • Early contract termination
  • Contract violation (unnegotiated Sync and Delay_Req messages)
  • Leap second

4. G.8275.1

Network topology: line of BCs

  • Set-up
  • Basic interoperability
  • GM failover test
  • Non-slave BC port test
  • Rogue master test
  • Injection of default profile GM
  • Leap second

5. IEC 62439

Network topology: HSR TC ring connected to PRP network. OCs included upon request

  • Set-up
  • Basic interoperability, cycle through GMs
  • PRP link failure
  • HSR link failure

6. C37.238 revision

Network topology: ring of TCs. BCs hand off to TCs. OCs included upon request

  • Set-up
  • Basic interoperability, cycle through GMs by changing priority 1 fields
  • Rogue master test
  • Injection of default profile GM
  • Injection of C37.238-2011 GM
  • Repeat above with and without VLAN tags
  • Leap second

7. IPv6 Default Profile

Network topology: line of TCs and BCs. OCs included upon request. End-to-end delay measurement.

  • Set-up
  • Basic interoperability, cycle through GMs by changing priority1 fields
  • Cycle through address scope settings

8. New Technology

New technology/profiles will be set up based on availability of multi-organization implementations. Possible networks include:

  • Enterprise Profile
  • SMPTE Profile
  • IEEE 802.1AS
  • White Rabbit
  • Experimental implementations of IEEE 1588 revision features
Further details about Plugfest preparation are also available on Plugfest Wiki, the login account is free to obtain while you submit the Plugfest Registration Form to


Please send comments and questions concerning the Plugfest to

Plugfest Co-Chairs

  • Douglas Arnold, Meinberg
  • Heiko Gerstung, Meinberg
  • Ken Harris, Rockwell Automation
  • Jeff Laird, UNH-IOL