have been (not counting its edges): 392 X 2 620 001 = 1027 megabytes As the executable simulation file v76.sim has consumed a maximum of 196 MB of RAM instead of 1027, we see that the Simulator has compressed the states in a factor of approximately: 1027 / 196 = 5.24 Note that this compression does not lose any state, as opposed to algorithms such as bit-state or supertrace (which consume less memory). 7.4.5.3 Replay an exception scenario The Simulator has generated two scenario files: v76.x1.scn and v76.x2.scn. A. In the Simulator, select File > Scenario > Load, and open v76.x1.scn. B. In the Simulator, press on Start MSC. C. Press the button Redo: All. The Simulator replays the scenario, reaches the exception, and displays: exception in transition dlca!dispatch : from_ready_input_v76frame No receiver for output v76frame from dlca!dispatch, line 468 of v76.pr 23 transitions executed time progressed from 0 to 24 end of scenario execution The Editor displays the MSC trace corresponding to the exception scenario, depicted in Figure 7.52: A attempts to establish DLC number 0; as the response L_EstabResp from B is too late, A has received an L_ReleaseInd, meaning failure of DLC establishment; the L_EstabResp from B finally arrives (E1 in the MSC), dispatch in B creates an instance of DLC; signal v76frame containing a SABME was saved, thus as dispatch in B is back to state ready, it inputs the signal; dispatch in B transmits an L_ReleaseInd and a v76frame containing a DM; reaching dispatch in A, the v76frame should have been transmitted to the instance of DLC by executing the transition TR1 shown in Figure 7.53; unfortunately, the instance is dead; therefore an output to a Null Pid is executed, detected by the simulator. 238 Validation of Communications Systems with SDL bug_exh4 dlca.dispatch inst_1_atob linst_1_btoanst_1_dlcb.dispatch PROCESS/ PROCESS/ PROCESS/ PROCESS/ v76test/dlca/ v76test/ v76test/ v76test/dlcb/ dispatch(1) inst_1_dlca.dlc datalink/ datalink/ dispatch(1) lestabreq(0) PROCESS/ atob(1) btoa(1) v76te