Evaluation of Labeled OBS with Home Circuits

Optical Circuit Switching (OCS) provides a good support for the services requiring high bandwidth and Quality of Service (QoS). When the character of network traffic changes from voice-oriented to data-oriented, OCS must cooperate with new switching mechanisms such as Optical Burst Switching (OBS) to improve performance. So a Hybrid Optical Switching (HOS) system is proposed. In HOS, different traffics are classified and both OBS and OCS can be processed. At the same time, delay buffer mechanisms, which are Fiber Delay Line (FDL) and electronic buffering, are introduced in HOS to solve the contention of OBS bursts. And a wavelengths classification mechanism, which assigns some wavelengths dedicated to OCS traffics, is provided to guarantee the QoS of OCS. To analyze the performance in theory, models based on Markovian theory and iterative method are provided. The results got by theory are accurate compared with simulations. The use of delay buffer can decrease the blocking probability of OBS and increase resource utilization. Wavelength classification mechanism benefits to improve OCS's performance.

Optical burst switching (OBS) is a switching technology that can efficiently operate in the optical core network using WDM technology and can also develop the future optical internet. The OBS switching technology presents a trade-off between the two switching technologies: optical circuit switching (OCS) and optical packet switching (OPS). This switching approach increases resource utilization compared with OCS technology and avoids the technological barriers of OPS networks. In OBS networks, many packets are assembled into one data burst at the edge node and a burst header packet (BHP) is sent before the burst transmission by an offset time in order to reserve the required resources in core nodes. This can cause security issues in the network and more specifically denial of service attacks that can occur if a source node is compromised. In this paper, we study a specific denial of service attack which we refer to as "BHP flooding attack", which prevents legitimate traffics from reserving the required resources at intermediate core nodes. We also propose the design of a reconfigurable BHP flooding countermeasure module that allows to counter against this type of attacks in an OBS network.

DWDM multi-mode switching network provides a unified approach to DWDM-based communications by allowing electronic packet switching (EPS), optical burst switching (OBS) and optical circuit switching (OCS) to be carried in the same network, and on the same router platform. In this paper, we present a sub-millisecond dynamic optical path setup scheme for the multi-mode switching router. More specifically, we devised a reconfigurable asymmetric optical burst switching (RA-OBS) scheduling scheme which integrates burst scheduling in the OBS mode, connection setup/teardown in the OCS mode, and channel reconfiguration in the EPS mode in a seamless fashion. The proposed scheme allows wavelengths to be dynamically shared among three different switching modes in real-time. The performance of the proposed integrated scheduler has been verified using OBS-ns2 simulator as well as in a hardware testbed. In particular, we have implemented the proposed integrated multi-mode scheduler in FPGA hardware in an optical switching testbed, and have demonstrated application triggered real-time sub-millisecond optical path setup. Another key contribution is that the proposed approach brings out the practical value of optical burst switching, which has stayed mostly in the theoretical regime in the past decade. We show that a truly dynamic optical network can be built with off-the-shelf optical components.

In optical switching paradigm, there are three approaches; optical circuit switching, optical packet switching, and optical burst switching (OBS). OBS is a technology that takes the best features of packet switching and circuit switching by providing a flexible infrastructure for carrying IP traffic and at the same time ensuring efficient utilization of the fiber link. In this paper we propose an effective contention resolution scheme to achieve minimum burst loss at core nodes. Algorithm of zero burst loss for bimodal burst switching is extended from single node star network topology to two node star topology. Scheduling at the core node, typically an optical cross connect (OXC), is performed in two modes i.e., Mode 0 & Mode 1. Mode 0 is for burst transmission between all directly connected edge nodes whereas Mode 1 is for burst transmission through remote core node to a particular destination edge node. Synchronization of the reservation request between the core nodes is a critical task in such a topology. In order to achieve minimum burst loss, using a small length of fiber delay line in recirculation mode results in an effective strategy.

On burst assembly in optical burst switching networks—A performance evaluation of just-enough-time

The great contributions in optical networks added the optical burst switching (OBS) networks that are outperforming in advance methods referred to as optical circuit switching and optical packet switching networks in the direction of switching and transmitting data through optical fibres. The critical and obligatory factors in OBS are assembling the bursts, routing, resource (such as transmission channels) scheduling, and burst segmenting for optimal transmission. Hence, the current research is focusing on these either of divergent factors of OBS and putting efforts to contribute optimal approaches to assemble, route, schedule or segment. In this paper, the segmentation scheme is investigated through simulation and it is shown that segmentation with void filling can achieve a significantly reduced burst loss rate.KeywordsOptical burst switchingBurst drop ratio

Statistical multiplexing at the optical layer has been considered a critical requirement in order to build the next generation of ultra-high capacity optical transport networks in a cost-efficient manner. However, even today, the state of the art of commercially available optical core networks is based on mature wavelength switching and routing technologies, which lack a transport and control plane architecture that can support statistical traffic multiplexing with guaranteed Quality of Service (QoS) across a wide range of QoS parameters even if they can support fast reconfiguration at msec time scales. For several years, most research efforts have focused on the concepts of Optical Burst Switching (OBS) and Optical Packet Switching (OPS), which are based on the hybrid use of electronic nodes and optical switches to exploit Time Division Multiplexing (TDM) in order to achieve statistical multiplexing and dynamic resource reservation over optical networks. While burst switching has been experimentally proven as a technically feasible technique, its performance suffers especially under strict requirements for QoS guarantees. In this paper we evaluate the performance gains that can be achieved exploiting statistical multiplexing over a large scale core optical network and we demonstrate the efficiency of the CANON architecture (Clustered Architecture for Nodes in an Optical Network) as a viable alternative to OBS, which can achieve both targets for statistical multiplexing gains and QoS guarantees at the same time.

We propose implementation methods to realize an optical hybrid switching combining OCS(Optical Circuit Switching)/OBS(Optical Burst Switching) and indicate the necessity of testbed. Then we discuss how to use optical hybrid switching for various applications.

In this paper the end-to-end TCP performance of a hybrid network composed of multiple Ethernet Passive Optical Networks (EPONs) in the access segment connected to the same edge node of a core network is evaluated. Three possible core network paradigms are considered: Optical Circuit Switching (OCS), Optical Burst Switching (OBS) and Optical Packet Switching (OPS). TCP performance is evaluated through simulations with ns-2. The hybrid network scalability is assessed by varying the number of EPONs connected to the same edge node and the number of Optical Network Units (ONUs) per EPON. Interoperability issues between access and core are investigated and the impact of the most important network parameters is highlighted. The three transfer modes considered for the core network are properly compared under different input conditions, discussing the related trade-offs that may lead to the most suitable choice based on the specific application scenario. Finally, some design issues are investigated with reference to emerging Long-Range EPON (LR-EPON) solutions.

Optical Burst Switching (OBS) networks provide a practical alternative to optical packet switching and optical circuit switching by separating control information from the primary data, sending the former on a separate control channel. However, this separation also renders OBS networks susceptible to a denial- or degradation-of-service attack (intentional or otherwise) when the data provisioned by a header packet on the control channel does not materialize. This paper addresses the problem of detecting and characterizing such problems and describes a method based on monitoring network traffic on the control and data channels. The method is evaluated on a publicly available dataset.

Hybrid optical switching networks make full use of the advantages of Optical Circuit Switching (OCS) and Optical Burst Switching (OBS). In parallel hybrid optical switching networks, edge nodes choose a switching mode for traffic and no longer change. The inflexible decision making of the traffic transfer mode leads to low resource utilization when the arrival rate of the OCS traffic is lower than the capacity of the light path. In this paper, a new transmission scheme is proposed to improve resource utilization for hybrid optical switching networks. When the traffic arrival rate of the light path is lower than the transmission rate of the light path, the OCS traffic flow is reshaped at the edge nodes to generate a series of voids. Then, several message packets are sent along the light path to inform the core nodes of the voids of the light paths that represent the unused bandwidth resources. To improve the resource utilization, the voids can be filled with data bursts by core nodes. The simulation results show that the new scheme can effectively reduce the burst loss rate and improve the link utilization of the hybrid optical switching network on the premise of a providing service quality guarantee for OCS traffic.

Hybrid optical networks (HONs) are the combination of different switching mechanisms such as Optical Circuit Switching (OCS), Optical Burst Switching (OBS) and Optical Packet Switching (OPS). The basic idea behind HONs is to integrate the advantages of different switching mechanisms. HONs are classified into three classes as: (1) parallel hybrid optical networks, (2) integrated hybrid optical networks, (3) client-server hybrid optical networks. In this article, we describe these classes in detail and a new integrated hybrid optical network called EISM (Efficient Integration of Switching Mechanisms in all-optical networks) is introduced. The proposed EISM method could perform optimally while considering some implementation criteria; such criteria include network bandwidth utilization, implementation complexity and also the domain of network performance by combining four switching mechanisms-OCS, long-OBS, short-OBS and OPS.

The paper presents the Multi-Service Photonic Network (MSPN) architecture, implementing the idea of optical circuit, burst and packet switching coexistence. We focus on the architecture using a layered perspective, and describe each layer functionality and technical implementation. Generic node structure gives a systematic description of MSPN functionalities through switching elements and transport interfaces. The implementation of new switching paradigms is particularly addressed by the discussion of the ways of transporting possibilities of optical packet/burst switching services over optical circuit switching services optical packet/burst. The MSPN support of different topological paradigms is of essential importance for the next generation optical transmission network deployment.

Optical burst switching (OBS) is a new optical switching paradigm where traffic can be switched and groomed at a lower level compared to optical switched circuit (OCS). While OCS is useful in carrying highly aggregated long-lived streams that require absolute quality of service (QoS) guarantees, OBS has a role in efficiently carrying bursty best-effort traffic. In this paper, we investigate further the comparative goodput and bandwidth efficiency of OBS and OCS using, on one hand, an adaptive deflection OBS routing that aims at minimizing the burst loss rate and, on the other hand, a routing and wavelength OCS strategy using the best possible routing paths for minimizing the blocking rate.

Dynamic optical interconnects using fast Optical Circuit Switches (OCS) are emerging as a scalable and energy efficient alternative to increasing network demands. Initial concerns regarding slow switching speeds of OCSs were recently overcome, with prototypes enabling circuit setup in a few microseconds. This can potentially broaden the classes of traffic patterns that can be carried efficiently by an alloptical interconnect. However, application performance on such newer interconnects has not been fully understood yet. In this paper, we explore the the gap between advances in faster OCS hardware and the potential success of such newer technologies in terms of application performance and cluster energy efficiency. We evaluate the performance of latencysensitive distributed applications running on a fast OCS environment, analyzing its impact to overall server and network energy efficiency. We also discuss scheduling inefficiencies of current fast OCSs and evaluate ideas to solve them. We find that while some distributed applications suffer minimal performance penalty when running on fast OCSs, more flexible schedulers, like the ones outlined in this paper, improve application performance and OCS efficiency by up to 2.44 times compared to the strategies in the literature. Dynamic optical interconnects using fast Optical Circuit Switches (OCS) are emerging as a scalable and energy efficient alternative to increasing network demands. Initial concerns regarding slow switching speeds of OCSs were recently overcome, with prototypes enabling circuit setup in a few microseconds. This can potentially broaden the classes of traffic patterns that can be carried efficiently by an all-optical interconnect. However, application performance on such newer interconnects has not been fully understood yet. In this paper, we explore the the gap between advances in faster OCS hardware and the potential success of such newer technologies in terms of application performance and cluster energy efficiency. We evaluate the performance of latency-sensitive distributed applications running on a fast OCS environment, analyzing its impact to overall server and network energy efficiency. We also discuss scheduling inefficiencies of current fast OCSs and evaluate ideas to solve them. We find that while some distributed applications suffer minimal performance penalty when running on fast OCSs, more exible schedulers, like the ones outlined in this paper, improve application performance and OCS efficiency by up to 2.44 times compared to the strategies in the literature.