System structure

The system consists of processes -or nodes- arranged in a user specified topology. Each process may refer to its PCB (Process Control Block; see below in this section for the PCB structure) and its local variables. Global variables also exist and can be accessed or not depending on the assumptions of the implemented protocol.

The communication among the processes is accomplished by exchanging messages. Each node has a number of ports equal to the number of its adjacent nodes. So each port is dedicated to one adjacent node. Each message is sent to and received from specified ports. The structure of the messages is standard.

The information about the number of processes, the system topology, the kind of timing, timing parameters is included in network description files and can change in different executions, as different networks are allowed to be used each time.

Note: The fields with (*) are often used by the user