Scalable Layer-2/Layer-3 Multistage Switching Architectures for Software Routers

A. BIANCO, J. M. FINOCHIETTO, G. GALANTE, D. MAZZUCCHI, M. MELLIA, F. NERI

San Francisco, USA

Conferencia; IEEE Globecom; 2006

IEEE

Software routers are becoming an important alternativeto proprietary and expensive network devices, because theyexploit the economy of scale of the PC market and open-sourcesoftware. When considering maximum performance in terms ofthroughput, PC-based routers suffer from limitations stemmingfrom the single PC architecture, e.g., limited bus bandwidth, andhigh memory access latency. To overcome these limitations, inthis paper we present a multistage architecture which combinesa layer-2 load-balancer front-end and a layer-3 routing back-end,interconnected by a standard Ethernet switch. Both front-endand back-end are implemented using standard PCs and opensourcesoftware. After describing the architecture, evaluationis performed on a lab test-bed, to show its scalability. Whilethe proposed solution allows to increase performance of PCbasedrouters, it also allows to distribute packet manipulationfunctionalities, and to automatically recover from componentfailures.