— Traffic engineering has been extensively studied to maximize network resource utilization while minimizing call blocking [1]. As the the demand for high data rate services over wide area networks (WAN) continue to grow [2], and as traffic patterns become subject to more frequent changes, resource utilization and the ability to guarantee quality-of-service become more important. However, accurate, predictive traffic models are difficult to construct [3], implying that the routing mechanism will need to adapt to the difference between the anticipated and the observed loads. Online routing based on network residual capacity plays an important role in such settings, since optimal offline solutions require knowledge of future traffic, rendering long-term optimization nearly impossible. shortest path first (SPF) based routing is fast and is currently the most widely-used online algorithm for optical networks. Many variants of SPF, like CSPF (Constrained SPF), have been proposed to...
Xiaolan J. Zhang, Sun-il Kim, Steven S. Lumetta