Adaptive hybrid optical switching: Performance and energy efficiency

Abstract

Hybrid optical switching (HOS) has the potential to provide highly efficient operation through combining various switching paradigms and different implementation options within the same network. The flexibility of choosing between circuit, packet or burst switching and electronic or optical implementation results in an improvement of both energy and data transport efficiency because the most appropriate method and less power consuming elements can be selected and used for transmission of data through the network while temporarily inactive elements are switched off or put in a low-power mode. In this paper, we introduce a novel network concept that we refer to as adaptive hybrid optical switching (AHOS) and present and investigate several architectures and realization options for AHOS nodes. The corresponding control plane comprises two layers, of which one implements routing, signalling and link management functions as defined in the GMPLS standard while the other is responsible for managing already established circuits and scheduling the transmission of packets and bursts. We present results on both performance and energy consumption for different AHOS node realizations, network configurations and traffic patterns, which prove the potential for a high improvement in energy efficiency with respect to conventional electronic packet-switched networks.

Hybrid Optical Switching for Data Center Networks

“…We do not consider in this paper the impact of different traffic patterns, that is, the portions of traffic served by circuits, long bursts, short bursts, and packets. In fact, we already evaluated this effect for core networks in [21], where we showed that an increase in traffic being served by circuits leads to slightly higher packet losses and a more evident increase of burst losses. Since in this paper we employ the same scheduling algorithms as in [21], we expect a similar dependence of the performance on the traffic pattern.…”

“…As a consequence, future data center networks should be highly flexible in order to serve each application with the required service quality while achieving efficient resource utilization and low energy consumption. To achieve high flexibility, in telecommunication networks hybrid optical switching (HOS) approaches have been recently proposed [21,22]. HOS combines optical circuit, burst, and packet switching on the same network and maps each application to the optical transport mechanism that best suits its traffic requirements, thus enabling service differentiation directly in the optical layer.…”

“…This operation will not require any change in the architecture of the HOS core node, which can be easily scaled to support very high capacities. Furthermore, for increased overall performance and energy efficiency we assume that the HOS core node is connected to a HOS WAN [21,22], but in general the core node could be connected to the Internet using any kind of network technology.…”

“…The GMPLS module is used to ensure the interoperability with other core nodes connected to the WAN. The GMPLS module is needed only if the HOS core node is connected to a GMPLS-based WAN, such as the WAN proposed in [21,22]. The HOS control plane manages the scheduling and transmission of optical circuits, bursts, and packets.…”