MPLS Research Articles

QoS-aware path switching for VoIP traffic using SCTP

Voice over Internet protocol (VoIP) has been a prevalent multimedia service nowadays. It allows us to transmit voice data over IP networks. However, quality of service (QoS) is a major challenge to VoIP services. It must provide similar quality to traditional public switched telephone network or cellular phone services. Therefore, QoS related protocols have become important for real-time applications. Multi-protocol label switch (MPLS) is one of the important techniques to improve the network performance from QoS point of view. It employs label swapping to speed up packet forwarding. However, when a large number of users utilize VoIP services, the network congestion issue still exists. It causes delay, jitter and packet loss that affect VoIP QoS. In this paper, we propose a QoS-aware path switching strategy by using stream control transmission protocol (SCTP) in MPLS network to improve the VoIP traffic. This was done by employing SCTP selective acknowledgment mechanism to report the transmission parameters of primary path and to determine the criteria to switch to backup path. Simulation results show significant improvement in VoIP QoS.

Comparative Analysis of QoS VPN Provisioning Algorithm on Traditional IP based VPN and MPLS VPN using NS-2

A virtual private network (VPN) is a private network that uses a public network such as the internet or Multiprotocol Label Switching (MPLS) network to connect remote sites of same or different organizations/networks together. VPN provides similar level of privacy, security, quality of service and manageability that privately owned network provides. This paper presents the comparative analysis of VPN provisioning algorithm, Modified Tree Routing Algorithm (MTRA), on traditional IP based VPN and MPLS technology based VPNs. MPLS based method of packet forwarding has many advantages over IP layer forwarding. Packets with the same destination arriving on different ports of the router can be assigned to different Forwarding Equivalence Classes (FEC). Conventional forwarding, on the other hand, can only consider information that travels with packet in the packet header. The simulator used to implement the algorithm is, Network Simulator version 2.30 (ns-2). NS-2 gives the packet level analysis of the network with animation. General Terms Networking

Free-Space Optoelectronic Switching Cores With MPLS for SANs Over WDM Ring Networks

With increasing demands on storage devices in the modern communication environment, the storage area network (SAN) has evolved to provide a direct connection allowing these storage devices to be accessed efficiently. To optimize the performance of a SAN, a three-stage hybrid electronic/optical switching node architecture based on the concept of a MPLS label switching mechanism, aimed at serving as a multi-protocol label switching (MPLS) ingress label edge router (LER) for a SAN-enabled application, has been designed. New shutter-based free-space multi-channel optical switching cores are employed as the core switch fabric to solve the packet contention and switching path conflict problems. The system-level node architecture design constraints are evaluated through self-similar traffic sourced from real gigabit Ethernet network traces and storage systems. The extension performance of a SAN over a proposed WDM ring network, aimed at serving as an MPLS-enabled transport network, is also presented and demonstrated.

Cross-layer end-to-end label switching protocol for WiMAX–MPLS heterogeneous networks

The integration of WiMAX networks and multi-protocol label switching (MPLS) networks, called WiMPLS networks, is the trend for nomadic Internet access in the fourth generation (4G) wireless networks. The base station (BS) in such heterogeneous networks will play the role of bridge and router between the IEEE 802.16 subscriber stations (SSs) and MPLS networks. However, there is no such integrated solution so far and the switching efficiency of the BS should be considered as well. This paper, therefore, adopts a cross-layer fashion (from network layer to MAC layer) to design the end-to-end label switching protocol (ELSP) for filling this gap. ELSP provides the mechanism of end-to-end (SS-to-SS) and layer 2 switching transfer for switching performance enhancement by assigning the SS with the MPLS labels (M-labels). The M-label can be carried by the IEEE 802.16e extended subheader within the MAC protocol data unit (MPDU), which is fully compliant with the IEEE 802.16e standard. The security issue caused by M-label usage is also concerned and solved in this paper. This paper also reveals an extra advantage that the switching delay of the BS achieved by ELSP can be as low as hardware-accelerated IP lookup mechanism, e.g., ternary content addressable memory (TCAM). Simulation results show that ELSP efficiently improves the end-to-end transfer delay as well as the throughput for WiMPLS heterogeneous networks.

A New Approach To Enhance Security In Mpls Network

As Multiprotocol Label Switching (MPLS) is becoming a more widespread technology For providing virtual private network (VPN) services, MPLS architecture security is of increasing concern to service providers (SPs) and VPN customers. MPLS suffers from a number of security issues as soon as an attacker successfully penetrates the core. This paper provides an approach to enhance security in MPLS network by integrating a new (k,n) Threshold Secret Sharing scheme with MPLS in which shares obtained are send over multiple disjoint paths. Our approach is implemented to measure time overhead on secrets packet transmission.

Optimizing QoS for Voice and Video using DiffServ-MPLS

Abstract: The new emerging QoS architectures are motivated by the desire to improve the overall performance of an IP network. Differentiated Services (Diffserv) define a model for implementing scalable differentiation of QoS in the Internet. Multiprotocol Label Switching (MPLS) is a fast label-based switching technique that offers new QoS capabilities for large scale IP networks. When an MPLS network supports DiffServ, traffic flows can receive class-based network treatment that provides bases for QoS guarantees. The objective of this work is to study the influence of the QoS mechanism via DiffServ-MPLS on network parameters such as jitter, delay and throughput. The comprehensive study showed general improvement in the throughput, jitter and delay particularly of voice and video transmission when using DiffServ-aware MPLS network as compared to pure IP only or MPLS only. Keywords: VOIP, MPLS, Diffserv QoS, OPNET 1. Introduction Various multimedia applications such as video streaming, VOIP and video conference are gaining demand bringing with it a massive congestion to the IP networks. With the emergences of multimedia applications in IP networks, bandwidth consumption has become a critical issue among the Internet community and Internet providers. Also a lot of the recent multimedia applications and services not only have bandwidth requirements, but also require other QoS assurances, like end-to-end delay, jitter or packet loss likelihood. These QoS requirements put new challenges on Internet service providers [1].

Hierarchical multiobjective routing model in Multiprotocol Label Switching networks with two service classes – a Pareto archive strategy

The article begins by reviewing a two-level hierarchical multicriteria routing model for Multiprotocol Label Switching networks with two service classes (QoS, i.e. with Quality of Service requirements, and Best Effort services) and alternative routing, as well as the foundations of a heuristic resolution approach, previously proposed by the authors. Afterwards a new variant of this heuristic approach, which includes a Pareto archive strategy, is described. In this archive, non-dominated solutions obtained throughout the heuristic are kept. At the end of the main procedure of the heuristic, these solutions are evaluated and a final solution for the routing problem is chosen using a reference point-based approach. The application of this procedure to two test networks will show, with analytic and discrete-event simulation models, that, in certain initial conditions, this approach provides improvements in the final results concerning the top-level objective functions, especially in more ‘difficult’ situations detected through sensitivity analysis.

Dynamic MPLS With Feedback

Multiprotocol Label Switching (MPLS) fasten the speed of packet forwarding by forwarding the packets based on labels and reduces the use of routing table look up from all routers to label edge routers(LER) , where as the label switch routers (LSRs) uses Label Distribution Protocol (LDP) or RSVP (Resource reservation Protocol) for label allocation and Label table for packet forwarding . Dynamic protocol is implemented which carries a Updates packets for the details of Label Switch Paths, along with this feedback mechanism is also introduced which find the shortest path among MPLS network and also feedback is provided which also help to overcome congestion, this feedback mechanism is on a hop by hop basis rather than end to end thus providing a more reliable and much faster and congestion free path for the packets .

The Transmission Multicast and The Control of QoS for IPV6 Using The Insfrastructure MPLS

Recently there has been several literatures about congestion control in an Unicast/Multicast environment and also some authors tried to be exhaustive as they discussed about managing Quality of Service (QoS) under DiffServ and IntServ. Although Multiprotocol label Switching (MPLS)Traffic and routing control, and also IPv6 control QoS was discussed by certain researchers these decades, but finding paper about MPLS and the way to control QoS for IPv6 is bit serious. MPLS routing control and multicast transmission are concerned with the handling of traffic flows during normal predictable network conditions. Overload control addresses the handling of traffic flows during unexpected or unusual conditions such as occur during holidays, catastrophes (e.g., earthquakes), or equipments failures. To save network resources, multicast transmissions are more and more adopted by the operators when the same information has to reach several destinations in parallel, such as in IPTV services, radio broadcast and video-clip streaming. Though, with respect to unicast transmissions, multicast sessions make the routing problem more complex with huge sets of trees to be evaluated. Multicast focuses to the scenario whereby a transmitter needs to forward a packet to multiple receivers; in this work, we use to create an Multicast Environment Group to shared data with opening UDP Tunnel and overlay topology to control message just like in an VPN, and give better management of QoS. Experimental results are provided to show the performance of the proposed technique compared with Unicast transmissions solutions in terms of bandwidth utilization and the QoS control and to illustrate the importance of the Congestion control in an MPLS Environment.

Research of Financial Informationization Construction system based on VPN Technology

With the continuous deepening of China's educational reform, “multi-campus” school system has become a common phenomenon in China colleges. It is a burning question that how to improve the efficiency of the financial management. Not only is VPN (Virtual Private Network) technology provide effective solutions for “isolated island” of financial information among campus but also VPN is a safe, reliable and cost saving new garrison networking. Through analysis of current university financial information systems status, based on MPLS (Multi Protocol Label Switching) and technology principles of VPN (Virtual Private Network) and combined with practical, financial information systems construction solutions are provided under multi-campus school conditions.

Including 10-Gigabit-capable Passive Optical Network under End-to-End Generalized Multi-Protocol Label Switching Provisioned Quality of Service

End-to-end quality of service provisioning is still a challenging task despite many years of research and development in this area. Considering a generalized multi-protocol label switching based core/metro network and resource reservation protocol capable home gateways, it is the access part of the network where quality of service signaling is bridged. This article proposes strategies for generalized multi-protocol label switching control over next emerging passive optical network standard, i.e., the 10-gigabit-capable passive optical network. Node management and resource allocation approaches are discussed, and possible issues are raised. The analysis shows that consideration of a 10-gigabit-capable passive optical network as a generalized multi-protocol label switching controlled domain is valid and may advance end-to-end quality of service provisioning for passive optical network based customers.

Analysis of Link Utilization in MPLS Enabled Network using OPNET IT Guru

This paper presents comparison study based on link utilization in the networks running over RIP (Routing information Protocol), OSPF (Open Shortest Path First) and MultiProtocol Label Switching (MPLS). Poor link utilization in case of RIP and OSPF is identified. A detailed simulation study is performed over MPLS network where we have shown MPLS network has utilized most of links resulting in congestion avoidance, low queuing delays. General Terms Computer Science, Network Technology, Network Simulation

Revealing MPLS tunnels obscured from traceroute

Operators have deployed Multiprotocol Label Switching (MPLS) in the Internet for over a decade. However, its impact on Internet topology measurements is not well known, and it is possible for some MPLS configurations to lead to false router-level links in maps derived from traceroute data. In this paper, we introduce a measurement-based classification of MPLS tunnels, identifying tunnels where IP hops are revealed but not explicitly tagged as label switching routers, as well as tunnels that obscure the underlying path. Using a large-scale dataset we collected, we show that paths frequently cross MPLS tunnels in today's Internet: in our data, at least 30% of the paths we tested traverse an MPLS tunnel. We also propose and evaluate several methods to reveal MPLS tunnels that are not explicitly flagged as such: we discover that their fraction is significant (up to half the explicit tunnel quantity) but most of them do not obscure IP-level topology discovery.

AIR: a Scalable Inter-domain Routing Protocol

As the Internet booms in size and evolves toward a ubiquitous information infrastructure, its interdomain routing mechanism is going to encounter predictable scalability problems in the future. This paper introduces a new scalable inter-domain routing protocol, AS-level Inter-domain Routing (AIR) which is tailored for the Internet that we can envision today. We design AIR at the routing granularity of the Autonomous System (AS) level and take advantages of the Multi Protocol Label Switch (MPLS) to facilitate the packet forwarding between ASes. Compared with the Border Gateway Protocol (BGP), AIR enhances the routing scalability of the next generation Internet while preserving the economic/administrative model of the inter-domain operations. Our design focuses on MPLS enabled AS-level transit routes and retains the flexibility of supporting inter-domain routing policies as well as rational inter-domain traffic engineering. Our proposal synthetically adopts various practical techniques and integrates them into a fruitful design.

Single-path and multi-path label switched path allocation algorithms with quality-of-service constraints: performance analysis and implementation in NS2

The choice of the path computation algorithm is a key factor to design efficient traffic engineering strategies in multi-protocol label switching networks and different approaches have been proposed in the literature. The effectiveness of a path computation algorithm should be evaluated against its ability to optimise the utilisation of network resources as well as to satisfy both current and future label switched paths allocation requests. Although powerful and flexible simulation tools might be useful to assist a network manager in the selection of proper algorithms, state-of-the-art simulators and network planning tools do not currently offer a suitable support. This study deals with the design and performance evaluation of multi-constraints path computation algorithms. To this aim, ad hoc software modules have been developed and integrated within the MTENS simulator. New single-path and multi-path computation algorithms have been proposed and compared in terms of number of accepted requests, success probability, network resources utilisation and execution time. Finally, some guidelines and recommendations for the selection of path computation algorithms have also been provided.

Possible Collision Avoidance with Off-line Route Selection

The paper describes the traffic flow problems in telecommunication networks based on the Internet protocol. The main aim of telecommunication network operator today is to offer an SLA (Service Level Agreement) contract to end users, with provided QoS (Quality of Service) for different classes of services. In order to achieve this, it is necessary to establish the routes between marginal network nodes meeting the network traffic requirements and optimizing the network performances free of simultaneous flows conflicts. In DiffServ/MPLS (Multi-Protocol Label Switching) networks traffic flows traverse the network simultaneously and there may come to collision of concurrent flows. They are distributed among LSPs (Labeled Switching Paths) related to service classes. In LSP creation the IGP (Interior Gateway Protocol) uses simple on-line routing algorithms based on the shortest path methodology. In highly loaded networks this becomes an insufficient technique. In this suggested approach LSP need not necessarily be the shortest path solution. It can be pre-computed much earlier, possibly during the SLA negotiation process. In that sense an effective algorithm for collision control is developed. It may find a longer but lightly loaded path, taking care of the collision possibility. It could be a very good solution for collision avoidance and for better load-balancing purpose where links are running close to capacity. The algorithm can be significantly improved through heuristic approach. Heuristic options are compared in test-examples and their application for collision control is explained. KEYWORDS: Telecommunication networks, collision avoidance, multi-constraint route selection, self-organizing systems, MPLS, QoS

Experimental Demonstration of Highly Resilient Wavelength-Switched Optical Networks With a Multivendor Interoperable GMPLS Control Plane

The backbone infrastructure for providing carrier-class services, such as a wavelength-switched optical network (WSON), usually involves equipment from multiple vendors. For intelligent path control in the WSON, it is highly desirable to introduce a unified generalized multiprotocol label switching (GMPLS) control plane, which is beneficial for reducing the operational cost and facilitating the dynamic service recovery. However, the interoperability issue of GMPLS-enabled WSON among multiple vendors has not been investigated to date, preventing its wide deployment in an actual operational scenario. Accordingly, in this paper, we experimentally present a highly resilient WSON with a multivendor interoperable GMPLS control plane. We successfully verify the interworking of the GMPLS control plane and wavelength-switching equipment from multiple vendors, and experimentally present dynamic wavelength path control and dynamic lightpath recovery from single-link failures that occur at different times and multiple link failures that occur simultaneously on a multivendor WSON testbed with both control and data planes. To the best of our knowledge, the interoperability trial of GMPLS-controlled WSON is a world first.

Distributed Sharing of Functionalities and Resources in Survivable GMPLS-Controlled WSONs

Sharing of functionalities and sharing of network resources are effective solutions for improving the cost-effectiveness of wavelength-switched optical networks (WSONs). Such cost-effectiveness should be pursued together with the objective of ensuring the requested level of performance at the physical layer (i.e., quality of transmission, QoT) and at the upper layer also in the case of a failure (i.e., survivability). This paper aims to apply the sharing concept to a WSON with QoT and survivability requirements (against single-link failures). QoT is guaranteed by resorting to regeneration of the optical signal in intermediate nodes. Survivability is guaranteed by resorting to path protection. To exploit the sharing benefits, the scarce regenerators are used for both regeneration and wavelength conversion (WC) leading to a sharing of functionalities. Also, the shared path protection mechanism is exploited to ensure survivability against single-link failures and make the sharing of network resources (regenerators and wavelengths) possible. The paper presents a novel distributed scheme (DISTR) for reservation of regenerators and wavelengths in generalized multi-protocol label switching controlled WSONs, in order to ensure the required level of QoT and survivability. Novel objects and selection strategies for the resource reservation protocol with traffic engineering extensions are proposed and evaluated. The DISTR scheme effectively combines regeneration and WC points, leading to a noticeable reduction of the regeneration usage with respect to the existing schemes. Moreover, a significant reduction of the blocking probability is achieved, independently of the wavelength selection strategy used.

Implementing novel reactive defense functionality in MPLS networks using hyperspeed signaling

Imagine if a network administrator had powers like the superhero Flash–perceived invisibility, omnipresence and superior surveillance and reconnaissance abilities–that would enable the administrator to send early warnings of threats and trigger mitigation efforts before malicious traffic reaches its target.This paper describes the hyperspeed signaling paradigm, which can endow a network administrator with Flash-like superpowers. Hyperspeed signaling uses optimal (hyperspeed) paths to transmit high priority traffic while other traffic is sent along suboptimal (slower) paths. Slowing the traffic ever so slightly enables the faster command and control messages to implement sophisticated network defense mechanisms. The core defensive capabilities offered by hyperspeed signaling include distributed filtering, teleporting packets, quarantining network devices, tagging and tracking suspicious packets, projecting holographic network topologies and transfiguring networks.Hyperspeed signaling is enabled by the Δc Algorithm, which is articulated as a distributed routing protocol for constructing hyperspeed label switching paths (LSPs) in multiprotocol label switching (MPLS) networks. The routing protocol, called the Δc Label Distribution Protocol, enables service providers to implement the novel reactive defense mechanisms. This paper describes the core defensive capabilities offered by hyperspeed signaling and the Δc Label Distribution Protocol. In addition to a theoretical analysis of the protocol, simulation results are provided that demonstrate its performance characteristics for various network and protocol configurations.

Research on MPLS Network Topology Aggregation Algorithm With The Effective Connected Dominating Sets

Using dominating set can aggregate the complex physical network topologies into simple virtual topologies and reduce the cost of the networks. In the Multi-Protocol Label Switching (MPLS) network, the dominating set constructed based on label router can effectively aggregate MPLS network topology and reduce the amount of Label Switching Path (LSP), so as to save the expenses of network maintain information. However, simply considering the size of dominating set can't guarantee the best performance of the networks after aggregating. Therefore, an improved algorithm based on breadth-first search spanning tree is proposed, considering the size of the dominating set, bandwidth performance of the nodes and path length between nodes, which can effectively extend the MPLS network, with excellent bandwidth performance and reduce the data transmission delay.