1. A method of simulating network connections, the method comprising: in a computer, generating a transaction by invoking a method model of a service model, the transaction including representations of network interactions; creating a sequence of actions, the actions defining network hardware activities including network actions performed by one or more source computer models, one or more network models, and one or more destination computer models, wherein creating the sequence of actions comprises at least one of (a) referencing an inter-site routing table to determine a next site to facilitate selection of the next network model and next computer model to simulate network hardware activities, (b) referencing a network-to-computer map to facilitate selection of a next destination computer model to simulate network hardware activities, or (c) creating a sequence of actions comprises referencing a computer-to-network map to facilitate selection of a next network model to simulate network hardware activities; and applying the sequence of actions to network hardware device models to simulate network connectivity.