This is the typical starting representation of a two node simulation, perhaps implementing the stop-and-wait protocol. The simulation is currently running but we could pause and then single-step through our protocol using the buttons. A total of 1622 messages have so far been delivered, and the Application Layer has not been presented with any ``incorrect'' messages. Our protocol is thus reported as being 100% correct.
In the next screen dump we've clicked on both node icons to display their output and attribute windows. All output on each node's main canvas is simply whatever the protocols write with the printf() function - here an annotation of the stop-and-wait protocol. The text on three of the five central buttons has also been defined by the protocol code, and the first button on top host window has recently been selected to report the state variables of the protocol. Such an output window is available for each node, even in large simulations.
Here we see an eight node simulation under execution. Some of the links appear thicker than others as they have recently carried more traffic. The global statistics window is being displayed and we can see that because of the relatively high number of corrupted and lost frames (resulting in re-transmissions), that the delivery efficiency is quite low. Another text-entry window has also been requested so that we may save the current topology to the indicated file. At present, the screen dumps presented here were taken of cnet (v1.3).
Here two subwindows have been selected to compare a specific set of link attributes with the global (default) link attributes. Both global and specific link attributes may be modified, while the simulation is running, by clicking buttons or dragging sliders. At present, the screen dumps presented here were taken of cnet (v1.3).
cnet was written and is maintained by Chris McDonald
(chris@cs.uwa.edu.au)