Generalized Multi-Protocol Label Switching Routing Research Articles

A Review on Deployment Architectures of Path Computation Element using Software Defined Networking Paradigm

In traditional Generalized Multi-Protocol Label Switching (GMPLS), wide variety of functionalities like, GMPLS signaling GMPLS routing and link management increased the computational complexity of a single GMPLS network node. In concern with this, in order to provide the best paths by concerning effective utilization of network resources and better quality of transmission, a dedicated Path Computation Element (PCE) has been introduced. Software Defined Networking (SDN) is a new paradigm that decouples the network control from the data plane. With Software Defined Networking, the design, build and manage of networks can be made cost effective and dynamic manner, by transforming the traditional networks into open and programmable networks. The objective of this paper is to provide different architectural models of path computation element using Software Defined Networking paradigm. Using these deployment models, a network operator can manage and operate both the circuit switching and packet switching networks, thereby reduce capital expenses as well as operational expenses.

GMPLS/PCE-Controlled Multi-Flow Optical Transponders in Elastic Optical Networks [Invited

Elastic optical networks aim at considerably improving network spectrum efficiency by using a flexible grid, while traditional optical transport networks operate with fixed frequency spacing. In such flexible networks, connections are accommodated into so-called “frequency slots,” which are dynamically established depending on client data rates and selected signal modulation formats. Key enablers to develop such a network infrastructure are bandwidth variable optical cross-connects (BV-OXCs) and BV transponders. For the latter, a multi-flow optical transponder (MF-OTP) is being considered as an appealing solution because of its support of high-rate super-channels as well as its elasticity, where optical connections can be reconfigured flexibly according to the required traffic requests. The dynamic selection (path computation) and automatic network configuration of both optical spectrum and MF-OTP resources are handled by a control plane entity. Herein, a distributed Generalized Multi-Protocol Label Switching (GMPLS) control plane combined with an active Path Computation Element (PCE) are adopted for the dynamic instantiation of flexgrid optical connections. To fully control the MF-OTP’s attributes and capabilities, specific extensions are required for both GMPLS routing and signaling.We propose and experimentally validate such extensions by considering two information models: partial and full. The difference between the models lies in information related to optical spectrum status (carried by the full model) on the MF-OTP interfaces attached to the BV-OXCs. Furthermore, a novel online routing, spectrum, and modulation assignment (RSMA) algorithm is conceived. The RSMA adopts both models to compute paths by trying to optimize the spectral link and MF-OTP resources when dynamically serving flexgrid connections. The experimental evaluation compares the models' attained RSMA performance with respect to the blocking probability as well as the setup and path computation delays.

Layer-preference policies in multi-layer GMPLS networks

We address the problem of routing Label Switched Paths (LSPs) in multi-layer networks based on the Generalized MultiProtocol Label Switching (GMPLS) paradigm. In particular, we pursue policies for choosing the appropriate layer to host a new LSP request, as we find that such layer-preference policies have significant impact on network performance. We discuss several simple layer-preference policies and we reveal why these simple policies ruin network performance in the long run. Consequently, we develop an efficient heuristics, the Min-phys-hop routing and wavelength assignment algorithm, to govern the selection of the best layer of a multi-layer network in which to host new LSP requests. We discuss the applicability of this algorithm with respect to the state-of-the-art GMPLS standards, above all, the GMPLS routing extensions to OSPF-TE. By extensive simulations, we justify that the Min-phys-hop algorithm produces close-to-optimal blocking and resource consumption under almost all possible selections of input parameters, and this is regardless of the wavelength and Optical-Electrical-Optical (OEO) conversion capability present in the network.

Experimental evaluation of GMPLS enhanced routing for differentiated survivability in all-optical networks

Future intelligent optical networks (IONs) are devised to support a wide variety of clients, each having their own reliability requirements, such as availability. These networks thus need to support differentiated recovery schemes fulfilling those requirements while achieving efficient network performance (e.g., resource usage). We specifically focus on dedicated path protection (DPP) and shared path protection (SPP) recovery within generalized multiprotocol label switching (GMPLS) all-optical networks. In this context, the standard GMPLS open shortest path first-traffic engineering (OSPF-TE) protocol does not convey the required routing information in order to achieve a desirable network performance. The novelty of this work is twofold. First, to present enhanced GMPLS routing approaches for both SPP and DPP recovery schemes that, besides maximizing resource usage, also address connection blocking mostly due to the wavelength continuity constraint. Second, to evaluate these implemented schemes in a real experimental ION named ADRENALINE testbed. A detailed description of the routing approaches along with their required extensions to current GMPLS OSPF-TE is provided. The experimental performance comparison is conducted considering three figures of merit: connection blocking probability, restoration overbuild, and connection setup delay. The evaluation of the aforementioned schemes may help network operators to select a survivability scheme for a given client.

Distributed virtual network topology control mechanism in gmpls-based multiregion networks

This paper proposes a distributed virtual network topology (VNT) reconfiguration method for Internet Protocol over a wavelength-division-multiplexing network under dynamic traffic demand. We have developed a simple heuristic algorithm for calculating the VNT for distributed control. A generalized multiprotocol label switching (GMPLS)-based routing protocol has been developed. The VNT is quickly reconfigured by setting up and/or tearing down lightpaths using a GMPLS signaling protocol. Traffic demand is measured at the ingress node and advertised by the extended GMPLS routing protocol. Performance of the proposed method is investigated using variable traffic model.