Measurement Based Reconfigurations in Optical Ring Metro Networks

Single-hop wavelength division multiplexing (WDM) optical ring networks operating in packet mode are one of themost promising architectures for the design of innovative metropolitan network (metro) architectures. They permit a cost-effective design, with a good combination of optical and electronic technologies, while supporting features like restoration and reconfiguration that are essential in any metro scenario. In this article, we address the tunability requirements that lead to an effective resource usage and permit reconfiguration in optical WDM metros.We introduce reconfiguration algorithms that, on the basis of traffic measurements, adapt the network configuration to traffic demands to optimize performance. Using a specific network architecture as a reference case, the paper aims at the broader goal of showing which are the advantages fostered by innovative network designs exploiting the features of optical technologies

Open-Source PC-Based Software Routers: a Viable Approach to High-Performance Packet Switching

Abstract. We consider IP routers based on off-the-shelf personal computer (PC) hardware running the Linux open-source operating system. The choice of building IP routers with off-the-shelf hardware stems from the wide availability of documentation, the low cost associated with large-scale production, and the continuous evolution driven by the market. On the other hand, open-source software provides the opportunity to easily modify the router operation so as to suit every need. The main contribution of the paper is the analysis of the performance bottlenecks of PC-based open-source software routers and the evaluation of the solutions currently available to overcome them.

Boosting the Performance of PC-based Software Routers with FPGA-enhanced Network Interface Cards

The research community is devoting increasing attention to software routers based on off-the-shelf hardware and open-source operating systems running on the personalcomputer (PC) architecture. Today's high-end PCs are equipped with peripheral component interconnect (PCI) shared buses enabling them to easily fit into the multi-gigabit-per-second routing segment, for a price much lower than that of commercial routers. However, commercially-available PC network interface cards (NICs) lack programmability, and require not only packets to cross the PCI bus twice, but also to be processed in software by the operating system, strongly reducing the achievable forwarding rate. It is therefore interesting to explore the performance of customizable NICs based on field-programmable gate array (FPGA) logic devices we developed and assess how well they can overcome the limitations of today's commercially-available NIC