MPLS Research Articles

A Hybrid Method for Signalling Transport in GMPLS Control Plane

This paper addresses the issue of signalling transport in control plane of the Generalized Multi-Protocol Label Switching (GMPLS) network. The two basic methods for establishing control channels in optical networks are the in-fibre-out-of-band and the out-of-fibre. Starting from the analysis of benefits and drawbacks of those methods, we propose and investigate a novel, flexible method for signalling transport, which is based on the analysis of the given network topology and combines the basic methods to achieve a trade-off between requirements for low latency and high reliability. Performance analysis has shown that, with hybrid method, data path setup times are close to the ones achieved with the in-fibre-out-of-band method, while preserving satisfying reliability and flexibility to integrate into multi-domain networks.DOI: http://dx.doi.org/10.5755/j01.eie.22.3.15310

A New Fast Backup Method for Bidirectional Multicast Traffic in MPLS Networks: Control Plane Procedures and Evaluation by Simulations

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.

AN ADAPTABLE SECURE SMART CARD ARCHITECTURE FOR INTERNET OF THINGS AND CLOUD COMPUTING

Internet of Things (IoT) and Cloud Computing paradigm is a next wave in the era of computing and it has been identified as one of the emerging technologies in the field of Computer Science and Information Technology. It has been understood from the literature that integration of IoT and cloud computing is in its infantile phase, that has not been extended to all application domains due to its inadequate security architecture. Hence, in this paper a novel adaptable secure smart card architecture for internet of things and cloud computing is proposed. This is a unique architecture adoptable for the public to have a secure access over diversified smart applications and services distributed in the cloud, anywhere, anytime, any device and any network irrespective of the underlying technologies in a smart environment with one IoT enabled User Adaptable Intelligent Smart Card (UAISC) through mobile devices. The cloud services are integrated and connected through an IP/MPLS (Internet Protocol / Multi-Protocol Label Switching) core System. Elliptic Curve Cryptography (ECC) is used to ensure complete protection against the security risks such as confidentiality, integrity, privacy and unique authentication. This model eliminates ambiguity, ensures security with enhanced performance and realizes the vision of “one secure smart card for any applications and transactions”. The performance of the proposed architecture is tested by establishing a test bed in a simulated environment and the results are reported.

An EFL Teacher’s Code Switching in a Young Learners’ Class

This paper presents the results of a single case study of an EFL teacher’s code switching which involved three languages including English, Indonesian, and Javanese in a young learners’ class. More specifically, this qualitative study aimed to analyze the teacher’s types of code switching and functions of her code switching in the teaching and learning process. Data from classroom observations, teacher’s interview, students’ interview, and students’ questionnaire showed that all of the teacher’s code switching were conversational and based on the structure of her switching; she did inter-sentential, intra-sentential, and tag switching. Further, those different types of code switching served four positive functions for the EYL teaching. Those included strategy to deliver clear material explanations, strategy to deliver clear task instruction, strategy to give encouragement, and strategy for disciplining the students.

An efficient routing algorithm based on segment routing in software-defined networking

Software-defined networking (SDN) is an emerging architecture that offers advantages over traditional network architecture. Segment routing (SR) defines the path of information through the network via an ordered list of multi-protocol label switching (MPLS) mechanisms on the packet headers at the ingress device, and this system makes SDN routing management more simple and efficient. SR can also solve some scalability issues in SDN. In this paper, we propose a routing algorithm for SDN with SR that can meet the bandwidth requirements of routing requests. Our algorithm considers the balance of traffic load and reduces the extra cost of packet header size in a network. Simulation results show that the performance of our algorithm is better than that of previously developed algorithms in terms of the average network throughput and the average rejection rate of routing requests.

Optimizing Flow Thinning Protection in Multicommodity Networks with Variable Link Capacity

Flow thinning (FT) is a concept of a traffic routing and protection strategy applicable to communication networks with variable capacity of links. In such networks, the links do not attain their nominal (maximum) capacity simultaneously, so in a typical network state only some links are fully available whereas on each of the remaining links only a fraction of its maximum capacity is usable. Every end-to-end traffic demand is assigned a set of logical tunnels whose total capacity is dedicated to carry the demand’s traffic. The nominal (i.e., maximum) capacity of the tunnels, supported by the nominal (maximum) link capacity, is subject to state-dependent thinning to account for variable capacity of the links fluctuating below the maximum. Accordingly, the capacity available on the tunnels is also fluctuating below their nominal levels and hence the instantaneous traffic sent between the demand’s end nodes must accommodate to the current total capacity available on its dedicated tunnels. The related multi-commodity flow optimization problem is 𝒩𝒫-hard and its noncompact linear programming formulation requires path generation. For that, we formulate an integer programming pricing problem, at the same time showing the cases when the pricing is polynomial. We also consider an important variant of FT, affine thinning, that may lead to practical FT implementations. We present a numerical study illustrating traffic efficiency of FT and computational efficiency of its optimization models. Our considerations are relevant, among others, for wireless mesh networks utilizing multiprotocol label switching tunnels.

Congestion Control Using Fuzzy Based LSPS in Multiprotocol Label Switching Networks

In this paper, we have proposed a fuzzy based decision making component for high volume traffic MPLS networks, by implementing Traffic Engineering, Quality of Service and Multipath routing. The approach explicitly proves to be successful in solving the issues and challenges pertaining to stability, scalability in high volume and dynamic traffic. Furthermore, it will work to handle congestion by higher link utilization and provides efficient rerouting of traffic along with fault tolerance in the network. In this research work, fuzzy calculations are done for fixing the attributes of the MPLS label(s), which is put on particular packet representing the Forwarding Equivalence Class. Fuzzy controller consists of two sub fuzzy systemsLabel Switched Path setup System (LsS) and Traffic Splitting System (TSS). The computation of dynamic status of Load and Delay is utilized by LsS to arrange the paths in preference order. The attained Link Capacity and Utilization Rate are employing by TSS for maintaining congestion free path. The impact of this is to facilitate, we have better decision making for splitting the traffic for different promising paths. This was apparent from the series of traffic scenarios. Observations are obtained using this realization.

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.

SDN orchestration architectures and their integration with Cloud Computing applications

Emerging cloud-based applications, running in geographically distributed data centers (DCs), generate new dynamic traffic patterns which claim for a more efficient management of the traffic flows. Geographically distributed DCs interconnection requires automatic and more dynamic provisioning and deletion of end-to-end (E2E) connectivity services, through heterogeneous network domains. Each network domain may use a different data transport technology but also a different control/management system. The fast development of Software Defined Networking (SDN) and the interworking with current control plane technologies such as Generalized Multi-protocol Label Switching (GMPLS), demand orchestration over the heterogeneous control instances to provide seamless E2E connectivity services to external applications (i.e. Cloud Computing applications).In this work, we present different orchestration architectures based on the SDN principles which use the Path Computation Element (PCE) as a fundamental component. In particular, a single SDN controller orchestration approach is compared with an orchestration architecture based on the Application Based Network Operations (ABNO) defined within the International Engineering Task Force (IETF), in order to find the potential benefits and drawbacks of both architectures. Finally, the SDN IT and Network Orchestration (SINO) platform which integrates the management of Cloud Computing infrastructure with the network orchestration, it is used to validate both architectures by evaluating their performance providing two inter-DC connectivity services: E2E connectivity and Virtual Machine (VM) migration.

An Improved Re-Route Model to Reduce Traffic in Multi-Protocol Label Switching Network

An Improved Re-Route Model to Reduce Traffic in Multi-Protocol Label Switching Network

IMPROVING QUALITY OF SERVICE THROUGH ROAD SIDE BACK-BONE NETWORK IN VANET

The vehicular ad hoc Networks (VANETs) are expected to support a large spectrum of traffic alert, dynamic route planning, file sharing, safety and infotainment applications to improve traffic management. User satisfaction plus in time delivery of real-time messages is the most significant quality evaluation criterion for vehicular applications. High mobility and rapidly changing topologies always lead to intermittent quality of services, higher delay and packet dropping issues in network. To improve the quality of services for multi-hop and dynamic environment, different types of solutions have been proposed. The article introduces multi-protocol label switching based on roadside backbone network to provide widespread, scalable, high-speed, robust quality of services and improve network efficiency. The simulation results showed that proposed model improves data transmission and routing performance in terms of data delivery, throughput, end-to-end delay and achieve adequate utilization of resources.

Design and Implementation of a Stateful PCE-Based Unified Control and Management Framework for Carrier-Grade MPLS-TP Networks

This paper presents the design and evaluation of a generalized topology discovery, operational monitoring, and provisioning (G-TOP) controller for a carrier-grade transport network. The G-TOP controller is a vendor-specific extension of the stateful PCE that integrates network topology discovery, path computation, and provisioning functions, but decouples the switch specific management framework. The G-TOP protocol enables the G-TOP controller to collect topology information, set up LSPs, and monitor state both from and to the management framework in a unified way. To validate the feasibility of the proposed framework, the author implemented a testbed using a multi-protocol label switching transport profile (MPLS-TP) switches and performed experimental testing. The experimental results show that the centralized control framework reduces provisioning time by approximately 68 ms and the autonomous management framework reduces fault recovery time by approximately 27 ms, while reducing the traffic load on the controller by several orders of magnitude compared to the OpenFlow approach.

Performance Evaluation of Routing Protocols for Video Conference over MPLS VPN Network

Nowadays video conferencing is a highly demanding facility in order to its real time characteristics, but faster communication is the prior requirement of this technology. Multi Protocol Label Switching (MPLS) IP Virtual Private Network (VPN) addresses this problem and it is able to make a communication faster than others techniques. However, this paper studies the performance comparison of video traffic between two routing protocols namely the Enhanced Interior Gateway Protocol (EIGRP) and Open Shortest Path First (OSPF). The combination of traditional routing and MPLS improve the forwarding mechanism, scalability and overall network performance. We will use GNS3 and OPNET Modeler 14.5 to simulate many different scenarios and metrics such as delay, jitter and mean opinion score (MOS) value are measured. The simulation result will show that OSPF and BGP-MPLS VPN offers best performance for video conferencing application

A scalable mechanism for establishing multi-point to multi-point traffic engineering paths in multiprotocol label switching networks

Network scalability is a major issue in core networks where multiprotocol label switching (MPLS) is largely deployed. In this paper, we propose a scalable solution for deploying bidirectional multicast trees in MPLS traffic engineering (TE) networks. The deployment of such trees is performed by defining the concept of multi-point to multi-point (MP2MP) TE label switched paths (LSP). Hence, one MP2MP TE LSP can be used instead of a full mesh of point to point (P2P) or point to multi-point (P2MP) TE-LSP in order to support value added applications such as video-conferencing. This leads to reduce the number of TE-LSPs in MPLS-TE networks and hence it improves their scalability. The paper presents the signalling procedures required to incorporate the new proposed MP2MP TE LSP in MPLS networks in addition to a simulation study in order to assess the scalability enhancement introduced by our contribution.

On distributed and centralised multicast path calculation in multi protocol label switched networks

Point to multi-point (P2MP) multicast paths in multi protocol label switched (MPLS) networks can be calculated by using whether centralised or distributed algorithms. Although centralised algorithms are very useful in optimising network resources and in deploying traffic engineering features (e.g. bandwidth reservation and fast reroute), they generally cause a heavy burden on the CPU and memory of network nodes. On the other hand, distributed algorithms are simpler and they do not impact the network nodes' performance (i.e. CPU, memory) at the expense of the absence of guarantee on the network performance (i.e. resource optimisation and traffic engineering deployment). The paper attempts to discover the performance of hybrid solutions based on extending distributed algorithms in order to achieve better network performance with a small impact on the nodes' performance. Two hybrid solutions are presented and valuable comparisons with the existing algorithms are performed. This contribution helps in deciding when and how to use each algorithm.

Achieving Optimal Traffic Engineering Using a Generalized Routing Framework

The open shortest path first (OSPF) protocol has been widely applied to intra-domain routing in today’s Internet. Since a router running OSPF distributes traffic uniformly over equal-cost multi-path (ECMP), the OSPF-based optimal traffic engineering (TE) problem (i.e., deriving optimal link weights for a given traffic demand) is computationally intractable for large-scale networks. Therefore, many studies resort to multi-protocol label switching (MPLS) based approaches to solve the optimal TE problem. In this paper we present a generalized routing framework to realize the optimal TE, which can be potentially implemented via OSPF- or MPLS-based approaches. We start with viewing the conventional optimal TE problem in a fresh way, i.e., optimally allocating the residual capacity to every link. Then we make a generalization of network utility maximization (NUM) to close this problem, where the network operator is associated with a utility function of the residual capacity to be maximized. We demonstrate that under this framework, the optimal routes resulting from the optimal TE are also the shortest paths in terms of a set of non-negative link weights that are explicitly determined by the optimal residual capacity and the objective function. The network entropy maximization theory is employed to enable routers to exponentially, instead of uniformly, split traffic over ECMP. The shortest-path penalizing exponential flow-splitting (SPEF) is designed as a link-state protocol with hop-by-hop forwarding to implement our theoretical findings. An alternative MPLS-based implementation is also discussed here. Numerical simulation results have demonstrated the effectiveness of the proposed framework as well as SPEF.

Performance Enhancement Architecture of VoIP Applications in Multiprotocol Label Switching Networks

In recent years, Voice over IP (VoIP) has impacted global telecommunications and networking tremendously. Traffic engineering and Quality of Service (QoS) guarantees for VoIP services pose a challenge for network researchers and designers. The repeated use of Internet Protocol shortest path towards the same destination may lead to unbalanced traffic situations and degraded network performance. Therefore, load balancing and link utilization become the critical functions in Internet Protocol routing for providing Quality of Service assurance for VoIP application. The aim of this work is to employ Multiprotocol Label Switching Network as a traffic engineering tool to enhance the QoS for VoIP applications. To achieve this, an effective Multiprotocol Label Switching Network load balancing architecture is developed that classifies the Internet traffic flows, routes the flows into multiple paths. Flow arrival rate, packet loss rate and delay are measured and taken as the input parameters and compared with the threshold values to identify the VoIP flow. Network load status is calculated by estimating the average buffer occupancy value and multipath routing is triggered when the network load is high to enhance the QoS. The investigated performance measures like throughput, delay and packet loss are reported to show the efficiency of the proposed technique for effective VoIP flows.

Multi SLA Aware Green Provisioning Mechanism for WDM Networks

This paper introduces a simple mechanism which attempts to reduce the energy consumption and corresponding Co2 Greenhouse Gas (GHG). This mechanism couples an emission reduction method with multiple service provider Service Level Agreements (SLAs) to ensure an acceptable Service Level Satisfaction (SLS). This purpose is accomplished by formulating and solving a multi-constrained optimization problem. The results show emission reduction with acceptable SLS. This mechanism can be used in different control environments, such as Software Defined Networks (SDN) or Generalized Multi-Protocol Label Switching (GMPLS).

Vendor-Interoperable Elastic Optical Interfaces: Standards, Experiments, and Challenges [Invited

This paper aims to review the status of standardization activities on the black link (BL) and corresponding alien wavelength concepts. It discusses experimental work on filterless optical networks conducted within a dedicated Deutsche Telekom project. The general prospects and existing challenges concerning elastic extensions of the BL are also assessed. Furthermore, we present relevant work on control and management plane interoperability comprising generalized multi-protocol label switching and transport software defined networking aspects. In the second part of the article, we report on the latest dual-vendor experiments on data plane interoperability in terms of digital signal processing technology for next generation 1.28 Tb/s PM-16QAM super-channels. Finally, we present a network reachability analysis based on the widely used Gaussian noise model in the context of data plane interoperability. This analysis estimates the network-wide impact of the single-vendor versus the dual-vendor approach.

Links Utilization in MPLS Networks Operating with Traffic Engineering Signal Protocols

Multiprotocol Label Switching (MPLS) is a technology that ensures efficient transmission with high speed and lower delays. Traffic Engineering (TE) signal protocols are usually used for active management of the MPLS networks for efficient utilization of resources. This paper presents performance investigation of MPLS TE signal protocols to get a guideline to utilize transmission links efficiently. Comparison is made between two TE signal protocols, namely Resource Reservation Protocol (RSVP) and Constraint-based Routing Label Distribution Protocol (CR-LDP). Simulation results are presented for three MPLS networks having different topologies which are implemented in OPNET (version 14.5) environment to support different applications in the absence and presence of quality of service (QoS) algorithms. The results reveal that MPLS network with CR-LDP TE signal protocol has better performance in the term of link utilization. The RSVP reserves certain paths for transmission while the CR-LDP utilizes almost all of the available links.