In this paper, for the first time, a cost efficient network slicing method is proposed for torus data centers based on optical packet switching transport. The torus optical packet switched rings are separately synchronized so that electronic regrooming is employed at the nodes connecting different rings, for the inter-ring transit of optical packet traffic. In the proposed network slicing method called “HYB-BOSS network slicing”, we introduce optical circuit switching over “network slicing paths” in order to leverage low-cost network operation. The resulting network has a hybrid optical packet/circuit switching architecture. Next, an optimal network planning tool is developed to evaluate the cost efficiency of HYB-BOSS network slicing in terms of required optical interfaces and optical fibers when compared with network slicing in purely optical packet switched torus. The numerical results show that HYB-BOSS network slicing can reduce the number of optical interfaces in a network by up to 33%.

This paper proposes a practical approach for multicast over optical packet switching ring topology. It is shown that MOPS can reduce the hardware complexity by using unicast feature to realize multicast while having the same bandwidth reduction like multicast compared to pure unicast. Meanwhile, MOPS can efficiently support reliable multicast. The performance of MOPS is evaluated in real mobile backhauling scenarios by means of simulations.

Existing Internet traffic classification techniques achieve impressively low misclassification rates, but do not provide performance guarantees for particular classes of interest. In this paper, we propose two novel online traffic classifiers - one based on Neyman-Pearson classification and one based on the Learning Satisfiability (LSAT) framework - that can provide class-specific performance guarantees on the false alarm and false discovery rates, respectively. We also present a preprocessor for our classifiers that predicts, after the reception of only a small number of packets, whether a flow will be 'large' (as defined by a network operator). Only these resource-intensive flows are passed to the classifier, greatly reducing the computation burden imposed. We validate our methodology by testing our approaches using traffic data provided by an ISP.

Protection against failure in high bandwidth optical networks can prevent significant potential losses of data but at the same time it requires a considerable fraction of the network resources to be reserved for it. Moreover, in optical networks suffering from physical layer impairments, inefficient use of network resources leads to significant increase in the blocking probability and higher vulnerability due to degradation of the QoT (quality of transmission) in the network. These trade offs call for the need to consider the physical layer impairments in designing higher layer protection schemes, i.e., a QoT-aware or cross-layer design. In this paper, we look at the performance of several link protection and link and path restoration algorithms in all-optical networks with realistic physical layer impairments, and propose a new cross-layer restoration method that exhibits both low blocking probability and low vulnerability ratio.

In WDM all-optical networks where electrical regeneration is not available, physical impairments due to propagation in the fibers, amplifier noise, and leaks between channels and in the switches cannot be removed at the physical layer. These effects cause calls, especially between physically distant nodes, to be rejected because they cannot meet minimum Quality of Transmission (QoT) requirements, as measured by signal bit-error rates. It is possible to mitigate physical layer effects at the network layer using appropriate Routing and Wavelength Assignment (RWA) algorithms. We present new RWA algorithms which account for physical impairments in their design and increase QoT and fairness among users without sacrificing low blocking probabilities in metropolitan-sized networks. We also present RWA algorithms that can sharply decrease blocking probabilities in regional-sized networks using optional channel coding. All algorithms are evaluated through simulation in realistic scenarios and shown to successfully mitigate crosstalk effects and to perform better in terms of QoT and network access fairness than traditional algorithms.

We present and evaluate a reinforcement learning-based RWA algorithm for all-optical networks subject to physical impairments. The technique is suitable for decentralized networks and is compared with other techniques with similar computational complexity.

We present and evaluate a reinforcement learning-based RWA algorithm for all-optical networks subject to physical impairments. The technique is suitable for decentralized networks and is compared with other techniques with similar computational complexity.

In this paper, we consider the problem of routing and wavelength assignment (RWA) in all-optical networks, where signals propagate in the optical domain (with no electrical regeneration) from end-to-end. In such networks, physical impairments are an issue and can cause calls to be blocked if a minimum quality of transmission (QoT) measured in terms of bit-error rate (BER) cannot be guaranteed for all calls, at all times. We focus on the routing component of RWA to incorporate QoT: we propose a novel RWA algorithm that finds a route based on both the network utilization and the physical impairments experienced over the tentative route. Our algorithm is fully decentralized and is shown using simulations to perform better than previously proposed algorithms on a regional-sized network.

As an optical signal propagates along a lightpath to its destination in distributed wavelength-routed optical networks, the signal's quality is degraded by transmission impairments, such as node crosstalk, which is induced by power leaking in the network nodes. Consequently, the bit error rate of the received signal at the destination can be unacceptably high. In this paper, a new adaptive wavelength assignment scheme based on wavelength spectrum separation technique is proposed to combat physical impairments in distributed optical networks. The proposed algorithm outperforms traditional techniques as measured by the blocking probability, adding little complexity.

There has been a significant amount of recent research on routing and wavelength assignment for DWDM networks suffering from physical layer transmission impairments. These algorithms attempt to increase the quality of transmission or service and are called QoT (quality of transmission) or QoS aware algorithms. However, protection has not been considered in this context so far, as far as we are aware. In this paper, we investigate the effect of physical layer impairments on dedicated path protection schemes. In dedicated path protection, every connection has resources reserved and dedicated on both a primary and a backup lightpath. While there is no difference in network performance whether the backup path is lit or kept dark in networks that are not transmission-impaired, lighting the backup path has an adverse effect on the network in transmission-impaired networks. By considering two different RWA algorithms - a QoT-aware one and a QoT-unaware one, we study the blocking performance and the vulnerability of the connections to failures for the two cases - dark backup and lit backup. Our results show that there are significant penalties in backup lit case, and that the QoT-aware algorithm considerably outperforms the QoT-unaware algorithm in terms of both blocking and vulnerability to failures.

We address the problem of efficient end-to-end network monitoring of path metrics in communication networks. Our goal is to minimize the number of measurements or monitors required to maintain an acceptable estimation accuracy. We present a framework based on diffusion wavelets and nonlinear estimation. Our procedure involves the development of a diffusion wavelet basis that is adapted to the monitoring problem. This basis exploits spatial and temporal correlations in the measured phenomena to provide a compressible representation of the path metrics. The framework employs nonlinear estimation techniques using l1 minimization to generate estimates for the unmeasured paths. We describe heuristic approaches for the selection of the paths that should be monitored, or equivalently, where hardware monitors should be located. We demonstrate how our estimation framework can improve the efficiency of end-to-end delay estimation in IP networks and reduce the number of hardware monitors required to track bit-error rates in all-optical networks (networks with no electrical regenerators).

In all-optical networks with no wavelength converters, signals are switched optically inside the nodes and therefore propagate over hundreds or thousands of kilometers with no electrical regeneration. Over such distances, physical impairments accumulate and can lead to serious signal degradation, resulting in poor quality of transmission (QoT) as measured by signal bit-error rates. The role of routing and wavelength assignment (RWA) algorithms is to accommodate incoming calls in optical networks over a route and a wavelength. RWA algorithms block calls if a continuous wavelength from source to destination cannot be found (wavelength blocking), or when the QoT of the call is not acceptable (QoT blocking). In this paper, we present an analytical method to evaluate blocking probability in all-optical networks, accounting for several physical layer impairments: intersymbol interference (ISI), amplifier noise (both are static effects that only depend on the network topology only) and node crosstalk (a dynamic effect that depends on the network status). We successfully validate our model through simulations on large scale networks with realistic physical layer parameters.

In all-optical networks with no wavelength conversion, signals must travel on the same wavelength over possibly very long distances. During transmission, the QoS of signals as measured by their Bit Error Rates is degraded not only by the propagation through fibers, but also by small optical leaks from other signals called crosstalk that occur in the nodes and cannot be removed at the physical layer. We present a set of Routing and Wavelength Assignment algorithms that mitigate the crosstalk effects on all-optical network operation. These algorithms incorporate QoS information at both the routing and the wavelength assignment steps and account for dynamic crosstalk to yield better performance in terms of average BER and fairness among network users without sacrificing blocking probabilities, as shown through simulation.