Standards families
UML communication diagram
Objects as nodes, links as edges, numbered messages along the links — the sequence diagram rearranged around structure.
uml.communication@1New DDN source
Why use it?
When the wiring matters more than the timeline, the communication layout shows who talks to whom at a glance.
When it helps
Reviewing collaboration structure: integration maps, object networks, message fan-out.
How to read it
- Boxes are participants; lines are links; numbered labels are messages in call order (1, 1.1, 1.2 …).
- Nesting in the numbers is nesting in the calls.
What you need
- The participants
- The links between them
- The ordered messages
Things to check
- Do not skip the sequence numbers — without them the diagram has no order.
- A message on no link is a topology error, not a style choice.
Scope of this diagram
Declared participants and message order; no protocol conformance or timing is claimed.
Work with the converted example
- Open the viewer and select
communication. Inspect the rendered view and its source. - Open the designer. Keep the selected profile and inspect its legal palette and property controls.
- Change one displayed title or an appropriate data value. Apply the edit and check the resulting diagram.
- Run the verifier and review its diagnostics before moving complete content into review.
- Download your edited DDN source to retain the change.
The example uses the indentation-based ddn-next-1 dialect. The language guide explains reusable definitions, dotted data rows and explicit property blocks.