Taxonomy feed.
In a pcap from a digital substation attention usually goes to GOOSE, SV, MMS and PTP. But useful diagnostics often live lower — in the MAC addresses. The article explains what an OUI is and how MA-L, MA-M, MA-S and CID differ, how to guess a vendor from the first octets, why a shared Source MAC on two IEDs breaks MMS and triggers MAC flapping, and what a digital-substation engineer should check on a first pass over a pcap.
CIGRE's first dedicated framework for virtualised IEDs will not publish until Q1 2028 — but the vPAC pilots that have to align to it are being commissioned now. Its scope is already public, through the working group's Terms of Reference and a framework article refeatured in ELECTRA 345 (April 2026): what is mandatory, what is deliberately out of scope, and what every 2026 vPAC pilot should already be doing in response.
Most digital substation projects are single-vendor, single-site proofs of concept. RTE — the operator of France's 2,600-substation transmission grid — decided to do something harder: build a fully digital, multi-vendor PACS from scratch, act as its own system integrator, and scale it across the entire network.