Operating systems support for programmable cluster-based Internet routers

As network routers evolve towards supporting ever higher-level networking functions beyond traditional network-layer and transport-layer protocols, programmability becomes a major design issue in network device operating systems (NDOS), which until very recently has been based on the type of operating system used in embedded systems. On the other hand, it is now possible to build high-performance Internet routers from off-the-shelf PC-class hardware, particularly with the use of clustering technology. The goal of the Suez project is to build a cluster-based Internet router using general-purpose processors as input/output link controllers and packet schedulers, and a Gbit/s system area network as the switching fabric. This paper presents the design and initial implementation of the Suez operating system, which features scalable real-time packet scheduling, cache-conscious routing table lookup, intra-cluster distributed buffer memory management and a highly efficient kernel extension mechanism for active networking using segmentation hardware