application executed user device 120 may simulate mesh network 105 and calculate among other things mean estimates of average times for path or path group unavailabilities and estimates of unavailability of paths or path groups as described further below the estimates may be output e g as a file displayed etc to a user the user may use this information for assessing service availability etc as such factors pertain to mesh network 105 according to exemplary embodiments mesh network 105 may be formulated in terms of nodes links circuits and paths a unidirectional circuit traverses one or more unidirectional links a unidirectional path traverses one or more unidirectional circuits mesh network 105 may include l unidirectional point to point links the bandwidth of a link x is denoted by b link x bits second a link can be in an operational state or a failed state a failed link has no available bandwidth the instantaneous available bandwidth of a link x at a time t is denoted by b link x t with initial condition b link x 0 b link x a bidirectional link can be modeled using a pair of unidirectional links a circuit is defined to be a unidirectional connection between two nodes 110 over a set of interconnected links 115 the total number of circuits in mesh network 105 is denoted by c the total bandwidth in a circuit i is denoted by b circuit i bits second the circuit i consumes the bandwidth b circuit i in each link of circuit i the circuit routing matrix.