Traffic burstiness has a significant impact on network performance. Burstiness can cause buffer overflows and packet drops and is particularly problematic in the context of small-buffer networks, which have been considered as a building block of the optical core infrastructure in the future Internet. To permit efficient operation of such networks, network traffic has to be "paced" by transmitting end-hosts or access links to avoid buffer overflows in the core. In this paper, we analyze the impact of traffic pacing on network performance using perturbation analysis. In particular, we study the impact of traffic burstiness on buffer occupancy of a tandem queueing network with infinite buffers. The input traffic is modeled as a marked point process which has the inter-arrival time and workload distributions containing scale parameters. Our results show that arrival traffic burstiness has a linear impact on the buffer occupancies. This linear relationship provides quantitative insight on the benefits of traffic pacing and thus provides understanding of how to improve the efficiency of small-buffer routers in the next-generation Internet.