One of the major challenges for optical network operators is related to realizing profitable networks that preserve the overall satisfaction of their end customers. This necessitates ensuring a controlled network resource usage while decreasing connection blocking probability. However, optical networks are witnessing the introduction of an increasing number of new services, each having different requirements. As such, the evolution towards resource efficient connection setup management strategies that provide differentiated call-blocking probability becomes inevitable. Building on the previous observation, we propose in this paper a novel connection setup management strategy. This latter aims to differentiate the blocking probability among different classes of lightpath requests, while avoiding the starvation of the lower class lightpaths. The main idea behind our proposal is to privilige higher class lightpaths via preemption and to protect the lower class lightpaths through rerouting. In this manner, the proposed strategy serves the double objective of minimizing the overall connection blocking probability and of realizing quality of service (QoS) differentiation. The previous claim is asserted through our simulation results that gauge the main benefits behind our proposed connection setup strategy. The simulation results drawn from the National Science Foundation Network (NSFNET) and the European Optical Network (EON) show that the proposed strategy achieves both differentiated and low blocking probabilities.

The worldwide network domain tendency to evolve towards dynamic quality of service (QoS) enabled optical networks is imminent. In such an evolution, improving connection setup conditions is considered to be one of the major requirements. This paper proposes a novel connection setup management approach. The rationale behind this proposal lies in considering the optical connection setup time requirement as a (timely increasing) priority indicator during the setup/provisioning process. From this viewpoint, we adapt the well known earliest deadline first (EDF) scheduling discipline to the particular case of optical connection setup management, which consists in giving highest priority to the connection request having the shortest setup time requirement. Another originality of this paper stems from the proposal of a computational method for the assessment of optical connection setup success probability under the proposed management approach. The latter parameter, that is the connection setup success rate, is an important indicator for both optical operators and clients.

A plethora of packet-scheduling algorithms have been proposed in the literature in order to meet the stringent time constraints of real time flows at an IP router level. In this regard, the so-called EDF algorithm attracted special attention since it is prominent for optimally managing flows with strict time constraints. However, EDF is complex and expensive as far as implementation is concerned, especially when compared with the standard FIFO algorithm. As a main contribution in this paper, we therefore propose a novel hybrid scheduling approach, which combines the optimality of EDF and the simplicity of FIFO. This approach allows reducing EDF's implementation complexity while making efficient use of its optimal flow management. Our simulation results underline the benefits behind such a proposal.

Optical networks are becoming an inevitable technology in the next generation Internet. Optical WDM networks require a control network for automatic and rapid configuration. A control plane is under standardization by the Internet Engineering Task Force (IETF) under the name generalized multiprotocol label switching (GMPLS). However, this control plane is unaware of the specifications of the services to be enforced. This work presents a policy-based management architecture adapted to an emerging kind of optical networks called hybrid photonic networks. Contributing to network flexibility, we present extensions to the management plane of these transparent wavelength and switching capable networks that provide the means to leverage their inherent capabilities. The proposed management architecture would provide optical network operators with the possibility to provision optical services, defined through high level service contracts, in an efficient and dynamic way.

One of the major concerns of optical network operators is related to improving the availability of services provided to their highest-class clients through the use of different protection schemes. However, the majority of the work concerning protection schemes considered the primary connections as equally important when contending for the use of the backup resources. As a first contribution we therefore propose an improvement of the existing shared protection schemes through the introduction of relative priorities among the different primary connections contending for the access to the protection path. Moreover, as a second contribution, we propose to include a novel service differentiation parameter, the service disruption rate of a connection, to provide differentiated services in a WDM mesh network, and we motivate the use of such a parameter with numerical examples. As a third contribution, we present a mathematical model for both the classical protection schemes and for the proposed priority-aware scheme. As a key distinguishing feature from existing literature we derive explicit analytic expressions for the average availability and service disruption rate resulting from the deployment of such schemes. By solving these models we then evaluate numerically the benefits of the service differentiation feature introduced in our scheme as well as the impact of the service disruption rate as service differentiator.

This document presents provisioning strategies for emerging hybrid optical networks. The idea is to make use of policy-based management that guides the behavior of a network through high-level declarative directives. In this regard and in the context of hybrid optical networks, policy rules are employed as the main means to extend the functionality of the control system and to complement its role in order to achieve the service provisioning.