A heuristic approach to solve the Table Lookup Bypass problem

In this work we investigate a new solution dealing with the increase of IP networks energy efficiency. The starting point of this work is Table Lookup Bypass (TLB), a new mechanism to reduce the energy consumption of a linecard overcoming the simple switch-off of network elements: TLB consists in bypassing the lookup operation performed by a router linecard and forwarding the incoming packets on a fixed outgoing interface. The paper defines four different heuristics able to detect a set of TLB operations that can be performed maintaining QoS constraints. The performance evaluation realized on a real network scenario shows that TLB can really improve the energy efficiency of IP network, both during peak hours and off peak hours: in this last case up to 90% of linecards can pass in TLB state.