Update from the Standards Vice President

Is my IP network working? Although this seems to be a simple question, it is really difficult to define what working actually means. One approach is to build a model for a working system and then make measurements on the real system to see whether it behaves as expected. In a new technology area like SMPTE ST 2110 and ST 2059 (PTP—Precision Time Protocol), there are likely to be differences between reality and the model.

To ensure the system is working, the difference needs to be categorized so that actions can be taken, and one of the following actions might be chosen:

• The model is right, but the implementation is wrong—fix the implementation.

• The model is wrong, but the implementation is right—fix the model.

• That was unexpected; both the model and implementation are wrong—fix them both.

• That was unexpected but irrelevant—ignore it.

To find the differences that fall into the first two categories, many tests with many different devices under different environments must be carried out, which requires a lot of brains to look at the model to see where it is strong and where it needs help. This is where SMPTE liaisons can help.

The SMPTE Drafting Group on PTP monitoring (TC-32NF-80 DG on ST 2059-2 PTP Device Monitoring) is developing an engineering document that will provide guidance on implementing PTP monitoring into professional media equipment. The group has already designed a YANG Data Model, based on Internet Engineering Task Force (IETF) RFC 8575, and extended the work to include additional containers covering further parameters that provide further information related to time transfer in an extended ecosystem.

YANG is a modeling language from the IETF defined in RFC 6020 and the SMPTE application. It is important that the model is sufficiently good to minimize the important differences between real-world equipment and theoretical performance of idealized behavior. The Drafting Group team has put their work, SMPTE RP 2059-15, into public committee draft (PCD) and is therefore publicly accessible online at https://github.com/SMPTE/rp2059-15.

To finalize the work, a large liaison outreach campaign has been launched to seek feedback on the proposed data model to ensure that it meets industry expectations in terms of capabilities and usability across several use cases.

SMPTE would appreciate feedback on the proposed PTP monitoring YANG data model, from any industry experts, via the GitHub tools that host the PCD, via conventional correspondence, and via an online survey available at https://www.surveymonkey.com/r/29GGT87.

These details can be shared with anyone who is actively working in this field to help us create the best and most usable standard that we can.

Our next Standards Meetings will be held virtually in the last week of August. Keep an eye out for information about how we will be supporting the Australia, New Zealand, and Southern Pacific Islands Sections by picking up the hot topics raised at their MetExpo event that will be held the preceding week.