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The evolution of software defined networking (SDN) has played a significant role in the development of next-generation networks (NGN). SDN as a programmable network having 'service provisioning on the fly' has induced a keen interest both in academic world and industry. In this article, a comprehensive survey is presented on SDN advancement over conventional network. The paper covers historical evolution in relation to SDN, functional architecture of the SDN and its related technologies, and OpenFlow standards/protocols, including the basic concept of interfacing of OpenFlow with network elements (NEs) such as optical switches. In addition a selective architecture survey has been conducted. Our proposed architecture on software defined heterogeneous network, points towards new technology enabling the opening of new vistas in the domain of network technology, which will facilitate in handling of huge internet traffic and helps infrastructure and service providers to customize their resources dynamically. Besides, current research projects and various activities as being carried out to standardize SDN as NGN by different standard development organizations (SODs) have been duly elaborated to judge how this technology moves towards standardization. [ABSTRACT FROM AUTHOR]

Bidirectional multicast mechanisms are used to support multi-point to multi-point (MP2MP) traffic such as video-conferencing. These mechanisms are deployed today in multi-protocol label switching (MPLS) networks using the connectionless mode in which traffic engineering (TE) features such as bandwidth reservation and fast reroute in case of link and/or node failure are not defined. Indeed, TE procedures are defined in MPLS for unicast and multicast point-to-multipoint (P2MP) traffic only. Hence, MP2MP traffic that requires TE procedures is carried out using a full mesh of P2P or P2MP paths. Similarly, a full mesh of P2P and P2MP backup paths should be predefined in order to fast reroute traffic in case of a node failure. This leads to a major scalability problem since MPLS TE paths incur heavy overhead burden on MPLS nodes (CPU and memory). In this paper, we emphasize on fast reroute procedures using MP2MP TE paths. In particular, we define the control plane procedures that should be established. In addition, we present a simulation study that demonstrates the scalability amelioration when using MP2MP TE paths for fast rerouting instead of full mesh P2P and/or P2MP paths. [ABSTRACT FROM AUTHOR]

One of the main concerns of network operators is that current routers are not scalable in order to meet future traffic requirements on the core Internet taking into account new applications. The next generation routers with petabit switching capacity are being built to serve higher demands. Their processing capability is enhanced by additional memory and computing resources on control and line cards with a very large number of high speed interfaces. However, the current routing software architecture is not able to fully exploit such an advanced hardware platform. This paper proposes a first distributed software architecture of MPLS/LDP targeting the next generation routers. We investigate the ability of offloading components of the current centralized architecture of MPLS/LDP on to line cards in order to share the load between the control and line cards. This allows the signaling to be achieved entirely at the line card level, hence, improving the robustness, scalability and resiliency of the system. Performance evaluation, considering the CPU utilization and the number of exchanged messages, is also presented. [ABSTRACT FROM AUTHOR]

This work presents a discussion about policies and architecture to aggregate Internet Protocol/Multiprotocol Label Switching (IP/MPLS) traffics within lightpaths. The scenario is that of IP/MPLS client networks over an optical network. It is well known that aggregating lower traffic flows (e.g., packet-based LSPs—Label Switched Path) within higher traffic flows (e.g., lambda-based LSPs) is considered an effective way to maximize the use of the optical network resources. In this work, the policies are divided into two groups. The first one, which solely considers the class of the flow (High Priority—HP or Low Priority—LP), consists of simple policies meant to aggregate packet-based LSPs within lightpaths. In this group, the policies we have defined intend to reduce the optical network overhead to remove and reroute LP LSPs. The second group presents more sophisticated policies taking into account the possibility of having to deal with further transport faults. In this case, the grooming is better planned and the defined policies tend to reduce the negative impact when a failure is detected in the optical transport network. Our approach has been implemented to validate the policies and the results for each group are showed and discussed. [ABSTRACT FROM AUTHOR]

Real-time traffic will be a predominant traffic type in the next generation networks, and networks with 100% reliability and availability will be required by real-time premium traffic. It is believed that QoS guarantees could be better provided by connection oriented networks such as Multi Protocol Label Switching (MPLS). These connection oriented networks are more vulnerable to network failure. Conventional path protection methods perform re-routing to cope with this. However, re-routing always causes packet losses and results in service outage. These losses are bursty in nature and highly degrade the QoS of the real-time premium traffic. Thus, 100% availability cannot be achieved by conventional methods. The novel path protection proposed in this paper recovers the bursty packet losses due to re-routing by using forward error correction (FEC) path. Therefore, it can provide network architecture with no service outage for such traffic. The numerical results show that the proposed method can achieve a very high availability for real-time premium traffic in future IP/MPLS networks. [ABSTRACT FROM AUTHOR]

In this paper different algorithms are presented and evaluated for designing Virtual Private/Overlay Network (VPN5/VONs) over any network that supports resource partitioning e.g. ATM (Asynchronous Transfer Mode), MPLS (Multi Protocol Label S witching), or SDH/SONET (Synchronous Digital Hierarchy/Synchronous Optical Networking). All algorithms incorporate protection as well. The VPN5/VONs are formed by full mesh demand sets between VPN/VON end points. The service demands of VPNs/VON5 are characterized by the bandwidth requirements of node-pairs (pipe-model). We investigated four design modes with three pro-active path based shared protection path algorithms and four heuristics to calculate the pairs of paths. The design mode determines the means of traffic concentration. The protection path algorithms use Dijkstra's shortest path calculation with different edge weights. The demands are routed one-by-one, therefore the order in which they are processed matters. To eliminate this factor we used three heuristics (simulated allocation, simulated annealing, threshold accepting). We present numerical results obtained by simulation regarding the required total amount of capacity, the number of reserved edges, and the average length of paths. [ABSTRACT FROM AUTHOR]

The increased bandwidth demand for new Internet applications suggests mapping IP directly over the wavelength-division multiplexing (WDM) layer. Since reliability is such a critical issue in these broadband networks, we propose an integrated design method which addresses the problem of survivability as viewed from the IP/MPLS layers but taking into account the failure mechanisms in the optical layer. This approach is becoming practical because of the emergence of generalized multiprotocol label switching (CIMPLS) as a multilayer control plane that can support the signaling required for coordinating the restoration mechanisms in multiple layers. The model relies on network calculus to evaluate a quality of service (QoS) metric as actually perceived by end users and computes a preplanned restoration scheme to recover from failures. We discuss the numerical implementation, the convergence and the solutions produced by the algorithm and show that the resulting network can provide the prescribed QoS guarantees for all failure states. [ABSTRACT FROM AUTHOR]

Many network muting situations commonly require backup paths that satisfy various Constraints on bandwidth, link or node selection, and ease of configuration. In this paper, we attempt to validate whether it is beneficial to have distinct algorithmic treatments of normal and backup path calculation, configuration, and maintenance. We present a modular suite of algorithms that enable us to manage normal and protection paths differently. In the process, we develop a simple extension of Minimum Interference Routing Algorithm for shared protection paths. We incorporate a distributed algorithm to separately calculate normal and backup paths in the network, using link state information, and present an evaluation of asynchronous dynamic reorganization of backup paths to reduce congestion in the network. Simulations demonstrate nontrivial quantitative reductions in blocking probabilities under certain conditions. We conclude that in order to choose an optimal algorithm for a protected QoS routing application, it is recommended to also consider a combination of two different algorithms for normal and backup paths. [ABSTRACT FROM AUTHOR]

Traffic control is a critical issue in connection-oriented packet-switching net- works such as asynchronus transfer mode, Mutiprotocol Label Switching, and Internet Protocol with IntServ. In this paper, we present a generalized concept, the virtual traffic path (VTP), to characterize the traffic control problems in connection-oriented networks. The VTP distribution typically addresses logical network design based on the physical network, and involves zboth the call level and the flow level controls. To date, various VTP optimization schemes for connection-oriented networks have been proposed. However, most reported schemes are based on the conventional flow assignment model. In this paper, we propose an extended flow assignment model focusing on the connection-oriented service with a non-linear objective function. The proposed model incorporates two concepts: VTP capacity and VTP flow, to perform the optimization. This model distributes traffic on all available VTPs evenly and takes the redundant capacities into account. In addition, we introduce a stochastic programming methodology to allocate VTPs when the injected traffic changes stochastically. Experimental results show that the proposed model and the stochastic methodology can significantly improve the performance of networks. [ABSTRACT FROM AUTHOR]