Many contemporary communication networks carry different types of traffics, each bearing specific characteristics of their own. The arrival process of packets outsourced from every single source node is approximated to a Poisson arrival process. Mostly, in network performance models, the exponential nature of the inter-arrival time in fault-free networks is determined by the dependency between inter-arrival times. But in most of the communication environments, in addition to minimizing packet delays and maximizing the network throughput, continuous functionality in the presence of faulty components has become a major issue. On such basis, the dependency phenomenon between consecutive service times as well as between service and inter-arrival times for packet queues in interconnection networks and in the vicinity of the faulty components can be of great importance. In this paper, we analyze the effect of such dependencies in packet queues through simulation experiments. We also study the behavior of an M/G/1 queue with Poisson processes in face of faults. This study can be used to justify the predicted packet delays obtained from analytical models under diverse traffic patterns and various network conditions and prove beneficial by enlightening the limitations of network analytical approaches in using approximation methods for evaluating network of queues.