As for organized systems of intercommunication, they were unknown even under the rule of a Pericles or a Caesar.
"The History of the Telephone" by Herbert N. Casson
The two systems have free intercommunication, ganglia being at the junctions.
"Special Report on Diseases of the Horse" by United States Department of Agriculture
As a result, twenty-five or thirty stations are considered the usual practical limit for intercommunicating systems.
"Cyclopedia of Telephony and Telegraphy, Vol. 2" by Kempster Miller
These practices are referred to as “cycle harvesting” or “workstation farms” and share the intercommunication network with external systems and services, not directly related to the coordinated multi-node computation.
Cluster Computing White Paper
Complexity Measures: The computational complexity of distributed deterministic algorithms using shared memory is commonly expressed in number and type of intercommunication primitives required and the maximum number of sequential read/writes by any single process in a system execution.
Randomized Two-Process Wait-Free Test-and-Set