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Simulation Scenarios Advanced Options

 

To set the advanced options, select the Advanced Options tab. The Simulation Scenarios window Advanced Options tab is displayed as shown in Figure 1.

Figure 1: Simulation Scenarios Window Advanced Options Tab
Simulation Scenarios Window Advanced
Options Tab

The Fast Re-Route Options are:

NormalSimulates the normal tunnel reroute. Does not consider the effect of the local repair during the simulation. Peak utilization reflects that during the normal situation.
FRR onlySimulates only the local repair. The resulting link peak utilization report reveals just the peak utilization experienced during the local repair.
Normal + FRRSimulates the FRR local repair first, followed by the normal primary tunnel reroute as established at the head-end router. The resulting link peak utilization report identifies the worst utilization, or max value of the transient detour and normal modes. A primary tunnel being detoured is marked down if it cannot be rerouted.

The Replay Up-Down Sequence pane allows you to use a custom failure simulation script. Choose the script file name by clicking Browse.

The following is an example of a custom failure simulation script:

Before you run an up-down sequence simulation, you must first select Simulation > Every Event or Simulation > When WAIT/RESET is Encountered. If you select When WAIT/RESET is Encountered, in this example, Link1 and Link2 are brought down first.

At the RESET line, the program attempts to route all unplaced tunnels in the network (and generate the appropriate reports), after which all links are brought back up and all tunnels are placed back in their original paths. The program then fails Link3 and Link4. Upon seeing the RESET LINK line, the program again attempts to route all affected and unplaced tunnels in the network (and append the appropriate reports), after which all links are brought back up.

However, this time, the tunnels are not placed back in their original paths; instead, the tunnels remain routed according to the paths found while Link3 and Link4 were down. The program then goes on to fail Link5 and Link6. At the WAIT line, the program attempts to route all unplaced tunnels (and append the appropriate reports), but does not bring up any links afterwards. Node1 and Node2 are then failed, and at the next RESET line, the program attempts to route all unplaced tunnels in the network while Link5, Link6, Node1, and Node2 are all down (and append the appropriate reports), after which all links and nodes are brought back up and all tunnels are assigned to their original paths.

After the program has finished running the script, you can view the appropriate failure simulation reports for information recorded at each of the RESET, RESET LINK, and WAIT lines.

If you choose to simulate Every Event, then the program runs a simulation after every network failure. In the example script, Link1 is taken down first, and the unplaced tunnels are rerouted and the appropriate reports generated. Then, Link2 is taken down (Link1 is still down) and the unplaced tunnels are rerouted. When RESET is encountered, all links are brought back up and all tunnels are placed back in their original paths.