A Study of the Impact of Network Traffic Pacing from Network and End-User Perspectives

As the demand on the Internet bandwidth keeps increasing, all-optical network architectures emerge as a promising solution to high-speed telecommunication networks. However, the performance of optical routers/switches is sensitive to the statistics of Internet traffic due to their limited buffer size, which weakens the optical routers´ capability of absorbing Internet traffic surges (known as burstiness), resulting in a high packet drop rate and, hence, lowering the quality of service. As a natural solution to the Internet traffic burstiness, pacing has long been studied and a variety of pacing techniques have been proposed in the literature. Nevertheless, the effect of pacing has not been conclusive. In this paper, we aim to answer the following questions: (1) in what situation pacing is beneficial, (2) does pacing harm short-lived flows, (3) does pacing affect the established fairness? We adopt in our simulation a newly proposed queue length-based pacing technique as a cure to the burstiness. The experimental results show that with appropriate parameter settings, pacing (1) significantly improves the performance of a moderately loaded small-buffer network, (2) brings little negative impact on short-lived flows in a nearly drop-free environment, and (3) is able to maintain the same fairness as achieved on the current Internet. These observations are of significant importance to a potentially wide adoption of small-buffer all-optical networks.