Directory /usr/xkernel/simulator/build/Template/example contains the configuration files needed to build and run the simulator. The graph.comp file is the only one needed to compile the simulator; the others must be in the working directory at runtime.
The files residing in the example directory configure a simulated network consisting of two Ethernets connected by a point-to-point link. Each Ethernet has two hosts, for a total of four. One host on each Ethernet runs the traffic protocol to simulate background traffic from TCP connections. The two other hosts run megtest, which uses TCP to stream one megabyte of data from one host to the other. Three flavors of TCP are configured into the simulator:
rtcp (TCP Reno), ttcp (TCP Tahoe), and vtcp (TCP Vegas). Any of these TCPs can be run on the traffic and
megtest hosts.
The simulator treats the graph.comp file differently than the user_level and standalone x-kernel s do. The simulator does not set up its protocol graph using the graph.comp; it only uses it to decide what protocols it must include in the executable. At runtime, the simulator creates the protocol graph using the xsim.data file. Note that in the example graph.comp file, megtest is configured over TCP Reno, but the xsim.data file runs it over TCP Vegas.
There is only one ROM file, and this file contains information for all of the hosts in the simulation. The example ROM file specifies the gateway to which a host will send when its IP datagram is addressed to a machine residing on another network. Note that the ROM entries begin first with the name of the protocol ( ip) and then the name of the host which uses that entry (e.g., h1n0 -- host 1 on network 0).
Most of the difficulting in configuring the simulator is how to specify the network you want to simulate. This specification is given in the file xsim.data, which is described elsewhere [1].