QoS aware optical packet switch with shared electronic buffers

Abstract

This work considers contention resolution in optical packet switches and proposes a switch architecture empowered by available technology which exploits a combination of wavelength and time domains to solve packet contention. An hybrid switch architecture based on space switching matrix and re-circulating links, equipped with wavelength converters and electronic buffers is described. The forwarding procedure is implemented by suitable scheduling which minimizes the number of wavelength conversions needed. Switch performance is evaluated by simulation to show the effects of combination of wavelength conversion and electronic queuing. The hybrid switch characteristics are exploited to design the switch in relation to application needs. To this end, service differentiation schemes are applied to traffic forwarding and evaluated. The results obtained outline how switch design optimization take advantage of the relationships between the employed technology and traffic needs.

Multi-granular traffic scheduling in hybrid optical interconnection

“…Contention resolution in the wavelength domain is obtained by means of wavelength converters [16]. In addition, contention resolution in the time domain can be obtained by electronic buffers and optical to electronic conversion [12], [14]. Balance between optical and electronic components must be found to optimize switch cost and match, at the same time, traffic performance requirements.…”

“…In this paper, starting from the hybrid architecture presented in [12], a practical approach to manage multi-granular network services and related traffic switching is proposed and evaluated. Multi-granular service support can be achieved in optical switching by suitably combining assessed architectural concepts with suitable scheduling algorithms to manage data forwarding according to application characteristics and needs [7].…”

“…Balance between optical and electronic components must be found to optimize switch cost and match, at the same time, traffic performance requirements. An example of how to combine different contention resolution schemes in the same optical packet switch, by exploiting complementary aspects of these different approaches, was presented in [12] and [17] for synchronous and asynchronous environments, respectively. In the former paper, the concept of hybrid switch which implements multi-domain contention resolution was firstly introduced as a general scheme, which consists of a non-blocking switching matrix with feedback wavelength converters and electronic buffers.…”

“…The related enabling basic building blocks, such as wavelength converters, optical logic gates and regenerators have been demonstrated in single-gate experiments, performing wavelength conversion at rates over 160 Gb/s or regeneration with bitwise processing capability over 40 Gb/s [9], [10], [11]. Many experiments and researches have been carried out in the last decade with the aim to support optical network flexibility through optical packet switching [3], [12].…”

Evaluation of packet scheduling in hybrid optical/electrical switch

“…Starting from a general scheme of the hybrid switch discussed in [18] and the architectural solution described in [19], this paper presents a detailed description of the scheduling algorithms needed to manage traffic forwarding according to the service class. Optical transparency, meant as the possibility to forward information in the optical domain, and packet loss performance are considered as far as the data path.…”