Light-trails: an optical solution for IP transport [Invited]

Abstract

We present a solution for IP-centric communication at the optical layer through a combination of a hardware platform and algorithmic implementation. The presented approach, termed light-trails, is shown to yield a reconfigurable networking platform in which optical connections of arbitrary duration can be established and torn down flexibly in negligible time, accommodating the dynamic traffic requirements of the IP world. The hardware platform and protocol are evaluated with tractable mathematical models validated through detailed simulation.

On Control Plane for Service Provisioning in Light-trail WDM Optical Ring Networks

“…Light-trail and connection provisioning have been theoretically studied in [6]. In [1], is proposed a Just-Enough-Time [19] based control mechanism that allows nodes to use light-trail bandwidth based on their position with respect to the convener of the light-trail. This approach gave a higher probability of success to nodes that were closer to the convener than to nodes closer to the end-node, leading to issues of fairness and hence inability to provision services [1].…”

“…In [1], is proposed a Just-Enough-Time [19] based control mechanism that allows nodes to use light-trail bandwidth based on their position with respect to the convener of the light-trail. This approach gave a higher probability of success to nodes that were closer to the convener than to nodes closer to the end-node, leading to issues of fairness and hence inability to provision services [1]. Solution to some of the fairness and dynamic bandwidth allocation problems were solved in [4] by proposing a 'dual auction' mechanism for bandwidth allocation in light-trails.…”

“…While the former calls for sufficiently advance networking technologies and control schemes, the latter requires sub-wavelength grooming (preferably for cost purposes in the optical domain) -requiring a paradigm shift from the conventional lightpath communication. Light-trails [1,2] a generalization of a lightpath have been proposed to provide sub-wavelength grooming [3], dynamic provisioning [3,4], and a low-cost solution [1,2]. Due to its unique architecture, a light-trail is analogous to an optical wavelength bus -nodes within a lighttrail arc, are able to communicate with one-another without any optical-switching.…”

SLiT (Strongly connected Light-Trail) for WDM Rings

“…Fundamentally, there are two differences between the SLiT concept and the original light-trail proposed in [1][2][3]. Architecturally, the node is modified to support a higher (twice) number of connections.…”

“…The SLiT solves the utilization issue by ensuring that the fiber is uniformly used. To do so, SLiT makes use of bidirectional EDFAs [4] as the only system enhancing feature as compared to the original light-trail drafts of [1][2][3]. At an acceptable delay penalty (consistent with that provided by light-trails) a SLiT is able to provide the necessary communication framework for emerging dynamic applications in both simplex as well as duplex communication modes.…”