"Communication diagram (called collaboration diagram in UML 1.x) is a kind of UML interaction diagram which shows interactions between objects and/or parts (represented as lifelines) using sequenced messages in a free-form arrangement.
Communication diagram corresponds (i.e. could be converted to/from or replaced by) to a simple sequence diagram without structuring mechanisms such as interaction uses and combined fragments. It is also assumed that message overtaking (i.e., the order of the receptions are different from the order of sending of a given set of messages) will not take place or is irrelevant." [uml-diagrams.org/communication-diagrams.html]
The template "UML communication diagram" for the ConceptDraw PRO diagramming and vector drawing software is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.