Simulated signaling Daemon (SimSwitch)

The SimSwitch is the simulated signaling daemon. The motivation behind the inclusion of a simulated signaling daemon is twofold:

• to enable research in ATM signaling even in the absence of ATM hardware.
• to allow researchers to debug their native ATM applications ``offline'', i.e. off the network, to ensure proper behaviour prior to running them live.

The simulated signaling daemon models an arbitrary set of $n$ signaling-capable hosts, each connected by a lossless link to a different port of a common $n$-port switch. Thus the simulated signaling daemon internally instantiates $n$ user-side UNI stacks, and $n$ network-side UNI stacks, each of which is quite similar to the single stack made in the SD; we will describe the principal differences. Because the simulated signaling daemon assumes lossless links between the switch and its $n$ hosts, each of the $2n$ UNI stacks lack a QSAAL layer, and does not ever communicate with an ATM driver. Furthermore, the $n$ network-side UNI stacks do not instantiate a service registration layer, and have a common routing module in place of the IPC layer.

Figure 2.3: The simulated signaling daemon (SimSwitch)