Ethernet Ring Protection (ERP) switching has emerged to provide sub-50ms of restoration times, allowing Ethernet technologies to expand beyond enterprises to Next Generation Metro and Backbone networks, providing much needed services to interconnect dispersed data centers. This paper considers the problem of efficiently designing and planning an Ethernet based metro network with ERP protection method. While previous recent work has addressed such design problem, none has considered the capabilities of exploiting multiple ERP instances, leaving behind some advantages that network providers could tap into to providing their customers with desirable quality of service support. Resource planning in ERP based Ethernet networks is however a complex problem due to the challenges associated with the logical link block selection as well as ring hierarchy selection. ERP instances add however another dimension of combinatorial complexity, making the design problem completely intractable. To address this issue, we resort to large scale optimization tools and present a novel primal-dual decomposition of the original problem using column generation. We show that our method is very scalable and obtain several design insights on various representative network instances.

This work proposes a simple and cost effective local access WDM-PON architecture that combines the salient features of both traditional static WDM-PON (i.e., dedicated connectivity to all subscribers with bit rate and protocol transparencies, guaranteed QoS, and increased security) and dynamic WDM-PON (i.e., efficiently utilizing network resources via dynamic wavelength allocation/sharing among end-users). Specifically, this paper proposes and devises a novel ring-based local access WDM-PON architecture that efficiently supports dynamic allocation of wavelengths/timeslots and sharing traffic as well as a truly shared LAN capability among PON end-users.

There is an emerging wide interest to transition from legacy WAN transport technologies to Ethernet-based technology. The current round of carrier Ethernet standards will successfully equip service providers (SPs) with the required tools to provide carrier-grade scalability and to provision and engineer connection-oriented point-to-point (P2P) packet trunks across a native Ethernet infrastructure. Building on these standards, this paper demonstrates how to support and implement full traffic engineering in a global-scale, two-tiered native Ethernet-over-WDM optical networking architecture. To achieve these objectives, several networking innovations are presented and developed including: 1) a GMPLS-based unified control plane that offers a tighter integration between layer-1 (optical transport layer) and layer-2 (Ethernet layer), 2) a fully distributed integrated routing and signaling framework for dynamically provisioning Ethernet switched paths (ESPs) at any bandwidth granularity including both full wavelength and finer granularity (sub-lambda) ESPs in an integrated Ethernet-optical networking environment, and 3) a novel notion of an integrated link-state advertisements strategy that is consistent with a fully integrated routing and signaling protocol

The problem of protecting purely multicast connections in WDM mesh network has recently started to receive some attention in the literature. In fact, WDM traffic is heterogeneous in nature and only part of the traffic is multicast and the rest is unicast, therefore we expect the presence of both unicast and multicast traffic in future optical networks. This paper studies the problem of dynamic provisioning of survivable heterogeneous unicast and multicast traffic in WDM networks. Specifically, we propose new protection schemes to provision and protect unicast and multicast connection requests against singlelink failures in WDM-mesh networks. The simulation results of the proposed protection schemes are compared with each others and with those found in the literature. The results showed that our proposed scheme TP-OSPT outperforms all other schemes for moderate and large multicast group size. On the other hand, our proposed scheme OCR performs the best for small multicast group size.

The problem of traffic grooming is a crucial constituent in designing WDM networks and has been extensively studied in the literature. Although it is expected that a part of the future traffic of WDM networks will be multicast, most studies of traffic grooming have assumed only unicast traffic. The paper investigates the problem of grooming multicast traffic in WDM networks. More specifically, different sequential single-hop and multi-hop grooming approaches are studied and compared to traditional non-grooming approaches. We also propose a hybrid approach that utilizes the combined resources at the logical and optical layers.

This work proposes a novel fully distributed Ethernet over star coupler-based PON architecture. The architecture uses a collision-free DBA scheme in which the OLT is excluded from the implementation of the time slot assignment. To implement a distributed control plane, direct connectivity (communicability) between the ONUs should be in place without imposing any constraint on the PON topology. In addition to the added flexibility and reliability associated with a distributed architecture, the performance of the proposed decentralized Ethernet PON scheme and the associated bandwidth allocation algorithms are shown to be as efficient as their centralized counterparts.

We investigate the problem of grooming dynamic multicast traffic in WDM mesh networks. This problem is equivalent to designing a light-tree based logical topology for multicast streams. It consists of four subproblems, namely routing, wavelength assignment, design of a light-tree based logical topology, and traffic-grooming. We develop different routing schemes to efficiently groom low-speed connections on the light-tree based logical topology. Numerical results demonstrate that the proposed approaches use the network resources more efficiently compared to the nongrooming approach and the approach of serving the multicast requests as separate unicast requests. Moreover, amongst the proposed techniques, the logical-first multihop grooming scheme MC-MHl outperforms all other schemes in terms of blocking probability and performance gain.

The paper proposes a novel IP-over-optical network interconnection model that takes the best features from both the overlay and peer models while avoiding their limitations. Specifically, the proposed model utilizes an optical layer-based unified control plane that manages both routers and optical switches (analogous to the peer model), while still retaining complete separation between the optical and IP layers of the overlay model. This is achieved by shifting the control plane functionalities previously associated with the IP layer to the IP/MPLS-aware, non-traffic bearing OXC controller modules located within the optical domain. In this architecture, better decisions can be made for provisioning and managing network resources, leading to their more efficient use. Based on the proposed model, an integrated dynamic routing algorithm, that takes into account the combined topology and resource usage information at both the IP and optical layers, is developed.

The efficient use of network capacity strongly depends upon the path selection procedure. In this paper we propose and evaluate efficient path selection algorithms for survivable optical networks with shared protection. Two distributed path selection algorithms are presented. The first approach maintains global information on network resource usage to determine link sharability and compute the optimal shared paths. The second approach, however, only relies upon local information maintained at each node. Subsequently, we present an analytical model to evaluate the performance of these path selection algorithms and show its accuracy through numerical examples.