For reenterable models of IP networks with dynamic routing according to RIP protocol, measuring subnets for QoS parameters evaluation have been essentially modified and extended. Online algorithms of statistical analysis have been specified by colored Petri nets. The mean and variance of the packet delivery time have been evaluated. As a result, the computation precision has grown and an essential speed-up of computations obtained because the online algorithms use a single pass over input data instead of two passes of classical algorithms. The same approach can be implemented for other statistical moments and spread on colored Petri net models of other networking technologies.