Green Routing/Switching and Transport

In this chapter, we provide an overview of energy‐aware routing solutions for backbone networks. After an introduction of energy‐aware strategies for network scenarios, we investigate the fundamental power consumption features of IP routers. In this context, we classify energy‐saving mechanisms in two categories: switch off and energy proportional. We focus our attention on switch‐off solutions, providing the general formulation of the Integer Linear Programming (ILP) problem considering two different scenarios, that is, flow‐based and destination‐based. Due to the complexity of the problem, different heuristics have been provided in literature; we describe the main ones, highlighting the key features of well‐known heuristics. Finally, we present an innovative energy‐saving solution, referred to as Table Lookup Bypass (TLB), based on the deactivation of forwarding functionalities inside a router line card.