Part 82: UAFX Networking
| Document number | OPC 10000-82 - title and status not confirmed |
|---|---|
| IEC designation | IEC 62541-82 - publication not confirmed |
| Colloquially | Part 82 |
| Group | UAFX |
Part 82 is our understanding of the networking part of the UAFX series - the layer covering how field-level traffic is carried and how the network is configured to carry it deterministically. Its title and whether it is released or draft are unconfirmed, and this page marks that rather than filling it in.
What is confirmed about UAFX networking
The transport underneath field exchange is PubSub, and the deterministic case is UADP carried directly in raw Ethernet frames using the reserved EtherType 0xB62C, addressed as opc.eth with optional VLAN identifier and priority code point. That path bypasses IP and UDP entirely, which is what makes it predictable and also what makes it demanding: it needs raw-socket privileges on the host and switches that honour the priority tagging. Part 14 also defines a datagram connection type whose quality-of-service category maps to the IP DSCP byte, plus message repeat count and delay with sequence-number deduplication at the receiver, which is the standard hook for time-sensitive delivery. All of that is confirmed and all of it is in Part 14.
What we are not stating
We have not confirmed this part's title, its number, or whether it is released or in draft, so we are not describing its contents or naming its types. We also have not verified from a primary source which IEEE 802.1 time-sensitive networking mechanisms the OPC UA work formally requires. The family usually named in this context covers clock synchronisation, a time-aware traffic shaper, a network configuration protocol and frame replication for redundancy, but treat that list as background knowledge rather than as a specification requirement until you have confirmed it.
How to specify network requirements today
Write the requirement against what can be tested. Name the PubSub transport profile - the Ethernet UADP profile for a layer-2 deployment, the UDP UADP profile otherwise - and state the cycle time, jitter and loss budget you need. Name the switch features you depend on, in IEEE terms, as a network requirement rather than as an OPC UA one. That specification is checkable with a packet capture and a traffic generator, which a part number is not.
What it defines
| Concept | What it is |
|---|---|
| The number and title - not confirmed | We believe the networking part of the series sits at 82, and we have not verified the number, the title or whether it is released or draft. |
| The subject matter | How field-level UAFX traffic is carried and how the network is configured to carry it within a bounded latency, as opposed to how the devices are modelled. |
| Ethernet layer-2 UADP - confirmed | PubSub over raw Ethernet II frames with EtherType 0xB62C, addressed as opc.eth with optional VLAN id and priority code point. Defined in Part 14. |
| Datagram QoS hooks - confirmed | Part 14's datagram connection type carries a quality-of-service category mapping to the IP DSCP byte, plus message repeat count and delay with receiver-side deduplication. |
| TSN mechanisms - not verified | Clock synchronisation, a time-aware shaper, a configuration protocol and frame replication are the usual components named in this context. We have not confirmed which the standard formally requires. |
| Relationship to Part 14 | The confirmed transport, security and message definitions are Part 14's. Whatever Part 82 adds sits above or alongside them, not instead of them. |
| Relationship to Part 81 | Part 81 defines the device and connection models. A configured communication flow eventually becomes traffic on the network this part governs. |
| What to cite instead | The PubSub transport profile URIs and Part 14 for the OPC UA side; IEEE standard numbers directly for the switch and clock requirements. |
Do you need to read it?
Network engineers being asked to support deterministic OPC UA traffic, and architects sizing a field-level project. The confirmed facts here - raw Ethernet UADP, the EtherType, the VLAN and DSCP hooks - are enough to have a productive conversation with a network team without citing an unverified part number.
Traps that trace back to this part
- Do not cite Part 82 in a specification from this page. Confirm the number, the title and the status against the publisher's own current reference documentation, and in the meantime write network requirements against Part 14's transport profiles and against IEEE standard numbers directly.
- Raw Ethernet PubSub is a privileged operation and a switch dependency. It needs raw-socket capability on the host - root or an explicit capability grant on Linux - and switches that actually honour the priority tagging end to end. A pilot on a desk switch proves nothing about the plant network.
- TSN is a network capability, not an OPC UA feature you enable. Buying UAFX-capable devices does not make the network deterministic, and configuring a time-aware shaper does not make a non-UAFX application deterministic. The two have to be specified and commissioned separately, by different people, against a shared latency budget.
Last verified 7 September 2026 against OPC UA 1.05.07. The specification parts themselves are published by the OPC Foundation. OPC UA Connect is an educational resource and is not affiliated with the OPC Foundation.