Inter-domain Path Computation Research Articles

A multi-population multi-tasking variable neighborhood search algorithm with diversity enhancements for inter-domain path computation problem

In recent years, as networks have become increasingly complex and expansive, network navigation faces new challenges in routing and resource utilization, particularly in the case of multi-domain networks. The Inter-Domain Path Computation under Node-defined Domain Uniqueness Constraint (IDPC-NDU) problem is one of many such scenarios. The problem requires finding the shortest path in a multi-domain network, but it cannot visit any domain twice. Since this is a proven NP-Hard problem, it is reasonable to approach IDPC-NDU from a meta-heuristics perspective. By integrating the search prowess of Variable Neighborhood Search (VNS) with the meta-learning capabilities of Multi-population-based Multitasking (MM), this paper proposes a Multi-population multi-tasking VNS (MM-VNS) algorithm to solve the Inter-Domain Path Computation under Domain Uniqueness constraint (IDPC-DU). In this combination, VNS is used to exploit solution space while meta-learning maintains diversity by transferring knowledge. Numerous experiments performed indicate the proposed approach finds better solutions in comparison with the state-of-the-art metaheuristics in many cases.

Node-depth based Genetic Algorithm to solve Inter-Domain path computation problem

Inter-Domain Path Computation problem under Node-defined Domain Uniqueness Constraint (IDPC-NDU) is an NP-Hard problem that applies to packet routing in multi-domain networks, particularly Hierarchical Path Computation Element (h-PCE) architecture. Its objective is to determine the shortest route between two specified nodes that visit each domain no more than once. In recent years, many proposals have been made to tackle this problem and improve existing algorithms. However, most of these strategies retain a potential weakness that lies in the complex encoding and decoding methods, which consume a lot of computer resources and computation time, especially for large-scale problems. For this reason, this paper introduces an effective Node-depth based Genetic Algorithm (NDEGA) for IDPC-NDU. We propose a novel solution encoding for the problem by using tree representation that helps to satisfy the domain constraint and makes the corresponding solution construction more practical. Instead of conventional encoding techniques, NDEGA is equipped with an improved Node-depth encoding, which is famous for its low time complexity and efficiency for tree problems. Besides, a corresponding decoding method, as well as node-depth search operators, are also well-developed for the problem. To examine the efficiency of NDEGA, we carefully conduct extensive experiments and compare our approach to many competitive baselines on a wide range of synthetic datasets. The empirical results demonstrate that our proposed algorithm significantly outperforms all compared algorithms regarding solution quality, convergence trend, and computation time and obtains the state-of-the-art performance for IDPC-NDU. Notably, our NDEGA achieves 65.17−85.66% solution quality improvement on average compared to the previous approaches while running faster, approximately 50−70 times.

A Particle Swarm Optimization and Variable Neighborhood Search based multipopulation algorithm for Inter-Domain Path Computation problem

It is a common occurrence nowadays for a network to be gigantic in size and complex in architecture. Network navigation thus faces many new problems in terms of routing and resource utilization, one of which arises in multi-domain networks. This paper focuses on the Inter-Domain Path Computation under Node-defined Domain Uniqueness Constraint (IDPC-NDU) problem, whose purpose is to find the shortest path between two nodes in a network under a constraint that such a path is only allowed to traverse each domain at most once. Considering that this is an NP-Hard problem, an approximate approach is more practical than an exact one. Meanwhile, Particles Swarm Optimization Algorithm (PSO) has been long known for its powerful ability to discover near-optimal solutions in a reasonable time; however, its application in discrete search space is limited. Therefore, we decide to use the multi-population framework, a sub-branch of multitasking optimization which allows information exchange not only between problems but also between different optimization heuristics, to improve upon the basic PSO method. Specifically, this paper introduces a hybridization between PSO and Variable Neighborhood Search (VNS). The encoding and decoding method are created specifically for the IDPC-NDU problem and for the PSO algorithm, and VNS serves to enhance further the algorithm’s ability to escape local optima. Experiments are carried out to prove the new algorithm’s efficacy, especially in the context of similar multitasking methods.

Adaptive Evolutionary Multitasking to Solve Inter-Domain Path Computation Under Node-Defined Domain Uniqueness Constraint: New Solution Encoding Scheme

In multi-domain networks, the efficiency of path computation becomes more and more important. The Inter-Domain Path Computation under Node-defined Domain Uniqueness Constraint (IDPC-NDU) is a recently investigated problem where its objective is to determine the effective routing path between two nodes that traverses every domain at most once. IDPC-NDU is NP-Hard, so the approximation approaches are suitable to deal with this problem for large instances. Multifactorial Evolutionary Algorithm (MFEA) is an emerging research topic in the field of evolutionary computation that can efficiently tackle multiple optimization problems at the same time. This study proposed an approach based on the combination of the Adaptive Multifactorial Evolutionary Algorithm (dMFEA-II) and Dijkstra algorithm for solving IDPC-NDU. The encoding and evaluating methods based on the permutation representation are also introduced, and the new individual representation is always to produce valid solutions. The proposed algorithm is evaluated on two types of instances. Simulation results demonstrate the superior performance of the proposed algorithm in comparison with the existing algorithms in terms of the quality of the solution.

A Particle Swarm Optimization and Variable Neighborhood Search Based Multipopulation Algorithm for Inter-Domain Path Computation Problem

A Particle Swarm Optimization and Variable Neighborhood Search Based Multipopulation Algorithm for Inter-Domain Path Computation Problem

Proactive H-PCE Architecture With BGP-LS Update for Multidomain Elastic Optical Networks [Invited

The hierarchical path computation element (H-PCE) architecture has been proposed to perform effective end-to-end path computation in multidomain elastic optical networks (EONs). In the H-PCE architecture a single parent PCE is responsible for inter-domain path computations, while a dedicated child PCE performs intra-domain path computations within each domain. In this scenario, effective inter-domain path computation is achieved only if detailed and updated intra-domain resource availability information is locally stored or retrievable by the parent PCE. Border Gateway Protocol has been recently extended to transport link state information (BGP-LS) that can be used to update the resource availability information at the parent PCE, thus improving scalability and effectiveness of the H-PCE architecture. Specifically, BGP-LS speakers located at each child PCE have been demonstrated to update the parent PCE with per-link spectrum slices availability information triggered by the reception of local Interior Gateway Protocol (IGP) advertisements. This paper proposes a proactive scheme to update the parent PCE, in which the generation of BGP-LS updating messages is not dependant on the IGP advertisements but automatically triggered by path computation requests at the child PCEs. The proposed scheme is applied during provisioning and restoration phases in a multidomain EON scenario and compared against two reference schemes. Simulation results show a significant reduction in terms of blocking probability and amount of exchanged control plane messages.

Multi-constrained path computation for inter-domain QoS-capable services

Computing inter-domain multiprotocol label switching traffic engineering label switched path MPLS-TE LSP through a pre-determined sequence of domains is quite straight as each path computation element PCE, using the backward recursive PCE-based computation BRPC, knows who is the next to be contacted in order to continue the computation. The optimality of the inter-domain MPLS-TE LSP path depends strongly on the choice of the pre-determined sequence of domains on which the calculation works. In this paper, we propose a novel procedure allowing a forward discovery of multiple inter-domain sequences and the computation of constrained inter-domain paths for MPLS-TE LSPs over these domains sequences. Other issues around the inter-domain path computation, such as route discovery and inter-domain loop avoidance, are investigated. Experimental evaluation shows that our solution is effective in terms of protocol and algorithmic efficiency and provides satisfiable performance with high success rate, reasonable message overhead and runtime.

Interdomain wavelength path control for translucent wavelength switched optical networks: from rationales to experiments

A translucent wavelength switched optical network (WSON), with sparse 3R regenerators to guarantee the signal quality of an optical connection, is a promising paradigm for a metro/ core network. This is because a translucent WSON can achieve performance comparable to that of an all-electronic switching (i.e., opaque) network with far lower network cost and a great reduction in power consumption. Because of its advantages, many recent research and standardization efforts have focused on translucent WSONs. However, most of them study the intradomain case, and issues related to multidomain translucent WSONs are largely open at present. In light of this, in this article, we present two possible strategies to improve interdomain path computation and lightpath establishment in a multidomain translucent WSON. Both approaches are experimentally demonstrated and quantitatively evaluated. Our aim is to provide feasible and efficient solutions for supporting a multidomain translucent WSON, as well as to obtain valuable insight into the proposed strategies through experiments, which will be beneficial for the potential industrial deployment of translucent optical networks.

Parallel lightpath provisioning under wavelength continuity constraint in multi-domain optical networks based on hierarchical path computation element

Inter-domain path provision under a wavelength continuity constraint (WCC), including path computation and resource reservation procedures, is a major challenge in multi-domain wavelength division multiplexing (WDM) optical networks, because of the requirement for confidentiality between the domains. Based on the hierarchical path computation element (PCE) architecture, this work proposed a path establishment scheme under a WCC to provide a fast inter-domain path establishment solution and decrease the influence of the WCC. The hierarchical PCE architecture consists of a single parent PCE serving as the arbitrator and multiple child PCEs responsible for the child domains. By cooperation between the parent PCE and the child PCEs, both inter-domain path computation and inter-domain wavelength reservation can be processed in parallel to accelerate and optimize WCC lightpath provisioning and thus to reduce the blocking probability. The effectiveness of this solution has been evaluated through simulations. The simulation results show that the proposed solution can achieve lower computation and reservation delays and thus lead to lower blocking probabilities on the multi-domain WCC paths.

A new framework for GLIF Interdomain Resource Reservation Architecture (GIRRA)

Many existing and emerging Scientific high-end applications (E-science) require end-to-end circuits interconnecting Grid resources for large data transfers. A few advanced networks, mainly National Research and Education Networks (NRENs), such as Surfnet, National Lambda Rail and Internet 2, now provide mechanisms for end-users to reserve and provision lightpaths via middleware referred to as Network Resource Mangers (NRMs). Although, some progress has been made in automated intra-domain lightpath services, inter-domain lightpath provisioning still requires manual intervention and presents several key challenges such as scalability of topology information exchanged, consistency and scalability of information model, security of access to the resources, hybrid networking and multi-layer lightpaths, and accounting and billing. In this paper, we describe a new architectural framework called Global Lambda Integrated Facility (GLIF) Interdomain Resource Reservation Architecture (GIRRA) with the goal to provide an integrated response to these challenges. We propose a new approach to model GLIF network domains and GOLEs as virtual switches and to describe their behavior, functionality, policy capabilities, and topology aggregation. We define an inter-domain path computation model to determine paths that meet constraints and access policy restrictions. We propose a security framework for authentication and authorization of users and a model for accounting and billing that aims to provide easy and secure access to the resources. Key aspects of the GIRRA solution are that it focuses on the inter-dependence between different challenges of inter-domain path provision, and it is built around already existing solutions for intra-domain resource provisioning.

An Inter-Domain Path Computation Scheme Adaptive to Traffic Load in Domains

The establishment of inter-domain traffic engineered paths is a requisite to accomplishing an end-to-end bandwidth guarantee and end-to-end resource optimization. Though the inter-domain paths must be reliable, it is difficult to compute suitable backup inter-domain paths in advance when the traffic engineering information is not disclosed outside of each domain. This means that the inter-domain path computation must satisfy the severe requirement of path establishment delay, since all inter-domain paths traversing the links in failure need to be computed after the failure occurs. Though several inter-domain path computation schemes have been proposed, their relative characteristics remain unknown. First, this paper classifies the conventional inter-domain path computation schemes into two types, i.e. end-to-end and per-domain schemes, and compares their performances under various traffic loads. Based on results of the comparisons, this paper proposes an adaptive inter-domain path computation scheme that can satisfy the severe requirement of the path establishment delay. In this scheme, the domain sequence from the source node to the destination node is divided into multiple sub-domain sequences according to the traffic load in each domain. The end-to-end path computation scheme is applied to the sub-domain sequences under heavy traffic loads, while the per-domain path computation scheme is applied to those under normal traffic loads. The simulation results show that the proposed scheme can adaptively satisfy the requirement for the path establishment delay while it maintains the optimality of path computation, even if the traffic load applied to each domain changes.

Interdomain path computation: Challenges and Solutions for Label Switched Networks

For label switched networks, such as MPLS and GMPLS, most existing traffic engineering solutions work in a single routing domain. These solutions do not work when a route from the ingress node to the egress node leaves the routing area or autonomous system of the ingress node. In such cases, the path computation problem becomes complicated because of the unavailability of the complete routing information throughout the network. This is because service providers usually choose not to leak routing information beyond the routing area or AS for scalability constraints and confidentiality concerns. This article serves two purposes. First, it provides a description of the existing and ongoing work in interdomain TE within the IETF. This information is currently found in various Internet drafts and has not yet been collectively presented in a single document. To this end, a summary of both existing path computation architectures - PCE-based and per-domain - is provided. Second, it compares two per-domain path computation schemes in terms of the total number of LSPs successfully placed and average number of domains crossed, without assuming availability of complete topology information. We notice that the two per-domain path computation schemes, proposed in [1, 2], have comparable path computation complexities and setup latencies.