International Journal of Emerging Technology & Research

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1 International Journal of Emerging Technology & Research Comparative Performance Evaluation Of Multimedia Traffic Over Multi-Protocol Label Switching using Virtual Private Network (VPN) Internet Cloud And Traditional Internet Protocol Networks Ezeh G.N, Onyeakusi C.E, Adimonyemma T.M, Diala U.H. Dept. of Electrical/Electronic Engineering, Federal University of Technology Owerri, P.M.B 1526, Owerri, Imo State, Nigeria. ABSTRACT This work investigated and discussed the performance of Multimedia traffic (Voice, Video and data) over Multiprotocol Label Switching (MPLS) on Internet Virtual Private Network (VPN) cloud. The motivation for this work is founded on the fact that the traditional IP network has various limitations viz-high delays, low latency, jittering, etc, hence very unsuitable for Multimedia traffic propagation over the internet backbone. For effective throughput, and good utilization of resources for Multimedia traffic, this work investigated a Multiprotocol Label Switching (MPLS) testbed (Multiconsole MPLS VPN Model) which ensures the reliable delivery of the real time services with high transmission speed and lower delays. This work considers Traffic Engineering (TE) as the major feature of MPLS as TE temporarily reduces the packet drops and latency by over 60%. Various testbeds were studied for performance analysis in this work. The adopted metrics in context includes Packet End-to-End delay (P v), Point-to-Point utilization (P u), and throughput (P t). From the research results, the MPLS VPN scenario gave Point-to-point throughput = 2.44% (1Kbps), Point-to-Point Utilization Pu = 34.09% (0.06), and Packet delay variation Pv = 37.5% (0.15Secs) while that of frame relay IP backbone scenario gave Point-to-point throughput (bytes/secs) = 97.56% (40Kbps), Point-to-Point Utilization = 65.91% (0.116), and Packet delay variation = 62.5% (0.250Secs). Consequently, the results show that for multimedia traffic propagation, using the above QoS metrics, MPLS VPN network offers better performance when compared with the traditional IP network model based on frame relay circuit thereby nullifying a stipulated null hypothesis stated in this work. Keywords:- MPLS, TE, IP, VPN, LSP, RSVP I. INTRODUCTION Contemporarily, with the advent of Internet cloud computing, there is now a shift on how applications and services are used on the internet. With a wide variety of applications and services provided on Internet, there is an increase in the number of internet users particularly realtime application users on internet [1].Since the conventional IP networkis highly insecure, and uses best-effort services which doesnot provide guarantee-of-services and Traffic Engineering (TE), leveraging multi-protocol Label Switching (MPLS) which is an emerging technology is shown to play an important role in the next 130

2 II. International Journal of Emerging Technology & Research generation networks. MPLS is considered ideal for Multimedia applications. Developing a network model that will scale gracefully to support large multimedia traffic in a secure manner without compromise to guarantee-ofservice, with predictable minimum delays and zero packet loss will be widely accepted. A candidate testbed called MulticonsoleMPLS VPN model is proposed and modeled while presenting it in this work. It is based on MPLS undelaying architecture to handle multimedia traffic in both small scale and complex environments. In the model, Label Switched Paths (LSP) is set based on constraints (considering bandwidth availability, administration policies, etc) which the packets are routed. The LSPs are virtual connections which are used to transmit the packets reliably (which is required for the multimedia traffic) in network cloud. Before the packet ingress into the label edge routers and label switch routers, an access list policy is blinded on traffic tunneled securely into the MPLS VPN. This forms a secured security framework in this work before the label switched packet switched security in the Multiconsole MPLS VPN domain. Besides, this work defines Multiconsole MPLS as a layer 2/3 enhancement over the existing MPLS networks. It utilizes Resource Reservation Protocol (RRP), and Path selection based on Available Bandwidth Estimation (ABE) to securely manage traffic from the sources to the Multiconsole MPLS VPN cloud. COMPARATIVE ANALYSIS OF IP AND MPLS NETWORK A. INTERNET PROTOCOL Internet Protocol (IP) allows a global network among an endless mixture of systems and transmission media [4]. The main function of IP is to send the data from the source to destination. Data is sent in the form of packets and this is routed through a chain of routers and multiple networks to reach the destination. In the Internet each router takes independent decision on each incoming packet. When a packet reaches a router, depending on the destination address in the packet header the router forwards the packet to the next hop by consulting itsforwarding table. The process of forwarding the packets by the routers is done until the packet reaches the destination. In conventional IP routing, to build routing tables, each router runs IP routing protocols like Border Gateway Protocol (BGP), Open Shortest Path First (OSPF) or Intermediate System-to-Intermediate System (IS-IS)[1].These protocols enable the routers to build the forwarding table. For forwarding the packet and controlling the routing tables, data plane and control plane are the main components. The data plane is a forwarding component which is responsible for forwarding packets from input interface to output interface on router. In the data plane forwarding, decisions are made by consulting the routing table. The control plane is the controlling component which is responsible for construction and maintenance of routing table. The control plan uses the information from the routing protocols such as open shortest path first (OSPF), Intermediate system to Intermediate system (IS-IS) and Border Gateway Protocols (BGP) in building and updating the routing table. These two planes are integrated in the traditional routers. 131

3 LIMITATIONS OF IMPLEMENTING MULTIMEDIA APPLICATION IN IP NETWORKS It is very challenging to implement the real-time application like VoIP in the conventional IP network. IP mostly work on the best-effort service which does not guarantee the delivery of the services. The following factors describe the limitations of IP networks to implement Multimedia/VoIP applications viz: - Routing in IP is designed to calculate the shortest path towards the destination but not the best path. - In IP networks routing is done in the Network layer which is slower than the switching. - Most of the links in IP networks are either under-utilized or over-utilized caused by its routing process, which results in congestion for over-utilized links. - IP networks are not scalable and TE is difficult to implement. Multimedia/VoIP application require guarantee of services with predictable minimum delay and low packet loss. This can be achieved by implementing the MPLS networks. In MPLS network, Label Switched Path (LSPs) are set based on constraints (considering the bandwidth availability, administration policies etc) on which the packets are routed. The LSPs are the Virtual connections which are used to transmit the packets reliably, which is desirable for transmitting the VoIP traffic. B. MPLS NETWORK Multiprotocol Label Switching (MPLS) is an evolving technology for high performance packet control and forwarding mechanism for routing the packets in the data networks [5]. MPLS is a switching mechanism that assigns labels (numbers) to packets, and then forward packets based on labels. The labels are assigned at the edge of the MPLS network, and forwarding inside the MPLS network is done solely based on labels. Labels usually correspond to a path to Layer 3 destination addresses; similar to IP destination- based routing. Labels can also correspond to Layer 3 VPN destinations (MPLS VPN) or non-ip parameters, such as a Layer 2 circuit or outgoing interface on the egress router. That means it acts like glue between layer 3 and 2 to make forwarding decision based on who is available, such as Any Transport over MPLS (AToM), quality of service (QoS), or source address [2,3]. Multiprotocol Label Switching (MPLS) is a tunnelling technology used in many service provider networks [4], MPLS domain has two main types of switches: MPLS core switch which consists of Label Switch Routers (LSRs) and the other is MPLS edge which consists of Label Edge Routers (LERs). Also, MPLS has evolved into an important technology for efficiently operating and managing IP networks because of its superior capabilities in providing traffic engineering (TE) and virtual private network (VPN) services [5]. MPLS is not a replacement for the IP but it is an extension for IP architecture by including new functionalities and applications. The main functionality of the MPLS is to attach a short fixed-label to the packets that enter into MPLS domain. A label is a short fixed entity with no internal structure. Label is placed between Layer2 (Data Link Layer) and Layer3 (Network 132

4 Layer) of the packet to form Layer 2.5 label switched network on layer 2 switching functionality without layer 3 IP routing [5,6,7]. Therefore Packets in the MPLS network are forwarded based on the Labels. 1. MPLS ARCHITECTURE The MPLS domain is described as a contiguous set of nodes which operate MPLS routing and forwarding [1]. MPLS domain is divided into MPLS core which consists of Label Switch Routers (LSRs) and MPLS edge which consists of Label Edge Routers (LERs). The main terminologies of MPLS technology are explained as follows [1, 8]: i. Label Switch Router (LSR) - Any router which is located in the MPLS domain and forwards the packets based on label switching is called LSR. When an LSR receives a packet it checks the lookup table and determines the next hop, before forwarding the packet to next hop, it removes the old label from the header and attaches new label. Figure 1: Label Switched routers [14] Figure 2: Label Edge routers [14] An LSR has the capability to understand MPLS labels andresponsible for receiving and transmitting a labelled packet on a data link in MPLS network. Three operations are associated with LSRs viz: pop, push and swap. InMPLS network, there are three types of LSRs [9, 10, 11, 12]: Ingress LSRs: receive an unlabelled packet, add a label to that packet andsend it via data link. Egress LSRs: receive labelled packets, remove the label or set of labels andsend them via data link. Intermediate LSRs: perform an operation on incoming labelled packet and switch the packet on the correct data link [11]. ii. Label Edge Router (LER) A packet enters into MPLS domain through LER which is called Ingress router. Packet leaves the MPLS domain through LER which is called Egress router. LER has an ability to handle L3 lookups and is responsible for adding or removing the labels from the packets as they enter or leave the MPLS domain. The LERs work as QoS decision points in MPLS network. By using port numbersin layer-4 of the packets, QoS policies can be established and managed [13]. The LERsare 133

5 responsible for adding or removing labels from the packets [12, 13]. iii. Label Distribution Protocol (LDP) - It is a protocol in which the label mapping information is exchanged between LSRs. It is responsible for establishing and maintaining labels. iv. Forward Equivalence Class (FEC) It is considered as the set of packets which have related characteristics and are forwarded with the same priority in the same path. This set of packets is bounded to the same MPLS label. Each packet in MPLS network is assigned with FEC only once at the Ingress router. v. Label Switched path (LSP) LSP is the path set by the signalling protocols in MPLS domain. In MPLS domain there exists number of LSPs that originate at Ingress router and traverses one or more core LSRs and terminates at Egress router. A LSP consists of a sequence of LSRs that switch a labelled packet through an MPLS network. In MPLS network, the first LSR of an LSP is the ingress LSR for thatlsp, and the last LSR of the LSP is the egress LSR. The intermediate LSRs areworking in between the ingress and egress LSRs [15, 16]. In MPLS routers, control plane and data plane are separated entities. This separation allows the deployment of a single algorithm that is used for multiple services and traffic types [17]. The label-swapping forwarding algorithm explains how the packets are routed in the MPLS domain which is described in the following steps, viz: i. When a packet enters the MPLS domain, a label of short fixed-length is inserted in the packet header by the Ingress router. FEC is identified from the label. ii. The packets belonging to one particular FEC are forwarded through the same path through the MPLS network even though all the packets do not have the same destination address. iii. The path on which the packets are forwarded to the next hop in the network is LSP. iv. Every hop in MPLS network forwards the packets based on the label but not on IP address. This is done until the packets reach the final hop in MPLS network and then the label is removed by Egress router and normal IP forwarding resumes. v. The Ingress and Egress routers are the LER s and the hops within the MPLS domain are LSR s. Figure 3:Label Switched Paths (LSPs) [14] C. TRAFFIC ENGINEERING The term Traffic Engineering (TE) refers to optimization of network configuration under given network and traffic constraints. This includes transport control to maximizethroughput under fairness constraints between users or routing to achieveresilience to router or link failure. However, in the literature, traffic engineeringis mostly associated with 134

6 adapting the routing function to the traffic situation tomake better use of available network resources [18]. Again, TE is a mechanism that controls the traffic flows in the networks and provides the performance optimization by optimally utilizing the network resources [18]. Figure 4: Traffic Engineering Process diagram.[19] In order to find a suitable routing setting, a number of steps need to be executed.these steps are illustrated in Figure 4 above. The first step is to collect the necessaryinformation about network topology and the current traffic situation. Most traffic engineering methods need as input a traffic matrix describing the demandbetween each pair of nodes in the network. Obtaining the traffic matrix in a largeip backbone can be a challenging task and the traffic matrix must be estimated from other available data. The traffic matrix together with network constraints such as network topology and link capacities is used as input to the optimizationof the routing. The outputfrom the optimizations need to be translated intoparameter values of the routing protocol in use and distributed to the routers. Omitted in the figure 4 is a feed-back loop from the output to the input of the traffic engineering process. A change in the routing will affect the traffic saturating the network because packets will be routed on different paths due to interactions between inter and intradomain routing. One approach to handle the feedback loop is to use control theoretic methods to design a routing function that converges to an optimal solution and is stable. This is referred to as reactive traffic engineering. Proactive traffic engineeringis another approach used to find a routing setting that isable to perform well under wide variety of traffic situations [7]. A third alternative is to omit the feedback loop and regard the traffic situation as independent of the routing; a fair assumption from the perspective of the communication end points. Some of the key features of TE are resource reservation, fault-tolerance and optimum Resource utilization [8] III. MPLS TE IMPLEMENTATION REQUIREMENTS The main objective of considering TE is to efficiently use the available network resources and increase service quality of applications on the Internet. The motivation behind MPLS TE is Constraint Based Routing (CBR) which takes bandwidth, policies and network topology (IP routing uses OSPF that calculates shortest path between the nodes and does not concernif that path has enough resources). Factors put into consideration for establishing a path(path refers to LSPs) in MPLS domain to forward the packets includes viz: Every LSR should consider complete topology of the network (only OSPF and IS-IS hold the entire topology). Every LER should be able to make an LSP tunnel on demand. 135

7 IV. VIRTUAL PRIVATE NETWORKS (VPN) The VPN is defined in this work as a network in which connectivity among multiple private Wide AreaNetworks (WANs) is deployed using shared MPLS IP infrastructure with the same policies as a private network [14]. It is an extension of a private intranet through a publicnetwork infrastructure to provide a secure, cost effective and reliable communicationchannel between two ends as depicted in figure 5. Figure 5: VPN consist of private networks connected through a public network [14] VPN Advantages The advantages and disadvantages of VPN have been outlined below [5, 6, 7]: VPN offers number of following advantages Lower cost of implementation Reduced support cost Better connectivity Better Security Better bandwidth utilization Scalability VPN Disadvantages There are following disadvantages associated with VPNs Internet dependent Lack of legacy protocols support A. MPLS VIRTUAL PRIVATE NETWORK (VPN) INTERNET Beside the use of MPLS in TE, it can also be used in implementing provider provisioned VPNs. Using MPLS for implementing VPNs is a viable alternative to using a pure layer-2 solution, a pure layer-3 solution, or any of the tunnelling methods commonly used for implementing VPNs. When deciding on implementing an IP/MPLS-based VPN, the service provider has two choices: A layer-3 approachcommonly referred to as MPLS Layer-3 VPNs. A layer-2 approach commonly referred to as MPLS Layer-2 VPNs. Evaluating the merits of a given approach should be based on but not necessarily restricted to the following aspects of the approach [9]: Type of traffic supported. Scalability. Deployment complexity. VPN connectivity scenarios that could be offered to the customer using this approach. Service provisioning complexity. Complexity of management and troubleshooting. Deployment cost. Management and maintenance costs. V. SURVEY METHODOLOGY This involves the study of physical network testbeds with the view to finding out the type of network architecture, topology, traffic/services propagated on the network, as well as the QoS metrics used to access such networks, etc. The advantage is that it gives an idea on how to formulate or develop a proposed 136

8 network model for the purposes of validating the intended hypothesis. The methodology leveraged in this research is the simulation approach. Empirical Research is based on experimentation or direct observation, i.e. evidence. This kind of research is often conducted to answer specific questions or to test hypothesis [20]. This work will present the simulation design and the results of empirical research while at the same time carry out confidence analysis to resolve the stated hypothesis. A= System of Interest(SOI), B= Specification model, C= DEVS scenarios (MPLS & IP), D= Test case Scenarios, E= Model Checking, F= DEVS Simulation, G= Result. C. CAPACITY MODELLING IN PROPOSED MPLS VPN ARCHITECTURE A. SIMULATION TOOL OPNET Modeller: This accelerates the research and development (R&D)process for designing and analysing the behaviour of devices, protocolsapplications, and communication networks. OPNET Modeller includes adevelopment environment for modelling of all network types and technologies including VoIP, TCP, OSPFv3, MPLS, IPv6, and Others [20]. The easy-to-use GUI structure of thismodeller enables users to design, simulate and view the results without having good programming knowledge or skills. B. SIMULATION A FRAMEWORK E B Figure 6: Simulation framework G C F D Figure 7:Proposed MPLS VPN analytical model The approach for capacity estimation is based on the use of Equations 1, 2 and 3. The MPLS VPN Network Operating Centres can enquire each router in the domain to supply the ingress Ip or egress Op and obtain the information about the available bandwidth on each of its interfaces. The most accurate approach will be to collect information from all possible sources at the highest possible frequency allowed by the LSP update interval constraints. This approach can be very efficient in terms of signalling and data storage. Furthermore, it can minimize traffic redundancies; memory requirements for data storage and the signalling effort for data retrieval.we define for a link between two nodes Xkand Yk 137

9 Let the input gateway capacity be given by I p= +.. (1) Let the output gateway capacity be given by OP= +. (2) Where j,n are integer values, Bw is the available bandwidth, X kis the input vector (Ingress) while y kis the output vector (Egress) Hence, the MPLS VPN Cloud Capacity is given by Cp=I p+o P (3) In this work, since the model seeks to achieve path information of already established LSP, the re-optimization is done primarily at the MPLS VPN cloud that is, the Network Operating centre (NOC) rather than in the edge routers. The algorithm below satisfies the optimization problem. In this case, it explains how to re-route an LSP that is already established to carry multimedia traffic on the network. Algorithm: Start ( ) 1. Define nodes X 1..X n 2. Filter incoming traffic & LSP (based on priority i.e video-voice-data). 3. Re-route LSP in the cloud 4. Receive LSP by nodes Y 1 Y n End; Form (1), the filtering reduces the number of unwanted or unauthorized LSP. This improves bottleneck on the network link using dijkstra shortest path with the weight function defined by: W(e)=1, h h 0,if otherwise. 4 The dijkstra shortest path aims to avoid bottlenecks or minimize it for multimedia traffic propagation. Let Nmin denote Min Value, N maxdenote Max value. The object function ( )Min (e) + (e) + (e) + (e) + (e). 5 Subject to traffic behaviour + + >0 6 Where c1,c2,c3,.cn denotes traffic cost functions, E R+ denotes the edge routers, X1, X2, X3 Xn toy1, Y2, Y3, Yndenotes the input and output vectors respectively. VI. SIMULATION AND RESULTS ANALYSIS Task: Hypothesis Formulation Null Hypothesis H0: There is no statistical variation between the QoS responses of traditional IP backbone for multimedia propagation and MPLS VPN backbone for multimedia propagation. Alternate Hypothesis Ha:There is statistical variation between the QoS responses of traditional IP backbone for multimedia propagation and MPLS VPN backbone for multimedia propagation. A. ASSUMPTIONS It is very hard to predict the behaviour of MPLS VPN backbone becausedifferent design and implementation factors are 138

10 involved in the network such as in modelling the VoIP traffic, voice codec, calls per hour, type of service (ToS), etc. This work will simulate the different MPLS VPN models by considering the QoS, RIPv2 or OSPF as IGP, and BGP as EGP. Also, 75% of link capacity is allowed for VoIP traffic to protect it from bursts. B. SIMULATION PARAMETERS Table 1 shows our simulation parameters in this research. In this work, to validate the system performance of the MPLS VPN model, OPNET Modeller was used to achieve the objective as discussed earlier. After setting up the model, a simulation run was carried out to generate our graphical plots shown in this work. Also, a consistency test was carried out which shows that the design model is stable and consistent before the simulation execution. Tables were configured and adapted in the MPLS VPN setup. Table 1: Evaluation Table for MPLS VPN and Frame Relay-IP Backbone Parameters MPLS-VPN Frame Relay IP No of Local 8 8 Clients No of remote 5 5 terminals No of 7 7 Gateway Servers No of Local 7 7 Servers Multimedia Enabled Enabled Traffic State profile (Voice, Video&Data) Application Enabled Enabled Profile (Voice, Video&Data) Internet Type MPLS VPN Frame Relay IP RSVP Enabled Enabled Table 2: Profile Attribute SN 1 LDP Enabled ConfigurationsStatus 2 Discovery Config. Enabled 3 Session Config. Enabled 4 Recovery Config. Enabled 5 Label Config. Enabled 6 Advertisement Policy No Delay 7 Signalling DSCP CS6/NC1 8 Re-optimization 3600 Timer(sec) 9 Delay (sec) Retry Timer (sec) Propagation TTL Enabled 12 Traffic Engineering BGP 13 Fast Reroute Status LSP Config 14 Revert Timer (Sec) LSP Config 15 Label Space Global GLA Allocation 16 CSPF Optimization TE Link Metric Cost 17 Number of Shortest path 5 C. PERFORMANCE EVALUATIONS For analysis of results, the following discrete event simulation (DEVS) statistics are chosen for MPLS VPN, viz: MPLS VPN Utilization (tasks/sec), MPLS VPN Throughput (pkts/sec) and Point-to-Point Queuing Delay (sec). A discussion on the obtained results is carried out below. 139

11 1. MPLS VPN THROUGHPUT (BITS/SECS) Throughput is a measurement of the average rate that data (in bits) can be sent between one user and another and is typically reported in kilobits per second or megabits per second. Throughput is, thus, computed using the amount of data in the payload area of the highest protocol layer (e.g., the UDP payload size) of the transmitted packets. As shown in figure 8, the throughput response is peak at 1kbps and remained stable throughout the lifecycle of the network. In this research, it was observed that the throughput response of figure 1 for IP frame relay maintained several oscillations and was unstable throughout the lifecycle of the traffic, though with a higher peak value of 30kps.This work then opines that optimal throughput behaviour is significant with MPLS VPN even at 1kpbs while at 30kbps its behaviour is unacceptable owing to the oscillatory trade-off. Hence, from the graphs, it is observed that there is an increase in the performance when the multimedia traffic is transmitted using MPLS technology than from frame relay IP backbone. 2. MPLS VPN TUNNEL DELAY (SECS) This is quite different from latency which generally does not vary for different protocols or traffic types. Figure 3 shows the MPLS VPN Tunnel Delay (Secs) or the packet end-to-end delay of MPLS and IP network model. There are many factorsthat determinethe quality of voice traffic as well as other traffic, which include the choice of codec, packet loss, delay, jitter as well as the medium of propagation. As shown in figure 3, the end-to-end delay in a network is about 0.15secs which is greater than 80ms. As such for MPLS VPN to establish acceptable VoIP calls, it will take a lesser time compared with the end-to-end delay in the plot of figure 7, which is 0.250secs. This work then argues that for all multimedia traffic, MPLS VPN network reaches the end-to-end delay threshold at lesser time compared with the traditional IP based network owing to its efficient and superior capabilities in providing traffic engineering (TE) over virtual private network (VPN) interfaces. Figure 8: MPLS VPN throughput Response (Bits/Secs) Figure 9: MPLS VPN Tunnel Delay (Secs) 140

12 3. AVERAGE UTILIZATION Traffic Engineering (TE) is a mechanism that controls the traffic flows in the MPLS VPN networks and provides the performance optimization by optimally utilizing the network resources. Some of the key features of TE are resource reservation, fault-tolerance and optimum Resource utilization. As shown in figure10, the MPLS VPN model reached a peak of about 0.06 (tasks/sec) and quickly dropped to about 0.01(tasks/sec) optimally while for figure 13, its utilization peak dropped from 0.116(tasks/sec) to 0.01(tasks/sec) showing that comparatively, MPLS have better resource utilization. Figure 11: (Bits/Secs) Frame Relay IP throughput Figure 12: Frame Relay IP End to End Delay Figure 10: Average Utilization for MPLS Figure 13: Frame Relay Utilization Plots 141

13 D. HYPOTHESIS VALIDATION ANALYSIS The simulation statistics were generated from figures 8 to figure 13 and the summarized statistics table is shown in table 3. From the table 3, the parametric variables (PV) viz: Throughput (P t),utilization (Pu), and delay (Pv), were computed after the simulation runs. Considering the algorithm and equation models developed, the introduction of these QoSparameters in the simulation Table 3:Summary of evaluation Analysis s/n QoS parametric variables (PV) 1. Point to point Throughput Pt 2. Point to point Utilization P u 3. Packet delay Variation P v IP Backbone 97.56% (40kbps) 65.91% (0.116) 62.5% (0.25secs) MPLS Backbone 2.44% (1kbps) 34.09% (0.06) 37.5% (0.15secs) testbed reveals that MPLS VPN model is more efficient as the QoSvariables Pt, Pu, and Pv for the various resources, as depicted in table 3. The overallresults highlight the effectiveness of MPLS VPN model for production deployment. From table 3, there is statistical variation between the QoS responses of traditional IP backbone for multimedia propagation and MPLS VPN backbone for multimedia propagation; hence the null hypothesis is rejected while we accept the alternate hypothesis. MPLS as an emerging technology ensures the reliable delivery of the internet services with high transmission speed and lower delays. The key feature of MPLS is its Traffic Engineering (TE) which is used for effectively managing the networks for efficient utilization of network resources. Due to lower network delay, efficient forwarding mechanism, scalability and predictable performance of the services provided by MPLS technology, this makes it more suitable for implementing real-time applications such as Voice and video. VIII. CONCLUSION VII. SUMMARY Multi-Protocol Label Switching, is quickly replacing frame relay and ATM as the technology of choice for carrying highspeed data and digital voice on a single connection. MPLS not only provides betterreliability and increased performance, but can often decrease overall costs through increased network efficiency. Its ability to assign priority to packets carrying voice traffic makes it the perfect solution for carrying VoIP calls. In this work, the performance of multimedia traffic over MPLS VPN Internet was carried out while making comparison with the conventional Internet Protocol (IP) network. Analytical models for capacity management and on-demand optimization was developed. Various system models with a LSP flow algorithm were derived. OPNET IT guru was used to simulate both networks and the comparison is made based on the metrics such as Point to point Throughput (bits/secs), end-to-end delay (secs) and 142

14 utilization (tasks/secs). The simulation results are analysed and it shows that MPLS based solution provides better performance in implementing the VoIP application. In this work by using the selected QoS metrics, an estimate justification on the use of MPLS VPN on today s bandwidth constrained networks will be widely accepted. This research can help the network operators or designers to determine the best type of network backbone to use in propagating multimedia traffics in real networks. IX. REFERENCES [1]. KeerthiPramukh Jannu, Radhakrishna Deekonda, OPNET simulation of voice over MPLS With Considering Traffic Engineering Master Thesis No: MSE ,June [2]. Reyadh Shaker Naoum, Mohanand Maswady Performance Evaluation for VOIP over IP and MPLS World of Computer Science and Information Technology Journal (WCSIT) ISSN: Vol. 2, No. 3, , [3]. Nader F.Mir., Albert Chien, Simulation of Voice over MPLS communications Networks, IEEE ICSS 02, conference. [4]. James Reagan, ''CCIP MPLS Study Guide 2ndEdition''. [5]. Liwen He, Paul. Botham Pure MPLS Technology. The Third International Conference on Availability, Reliability and Security, IEEE. [6]. Anders Gunnar, Towards Robust Traffic Engineering in IP Networks, M.Sc thesis, [7]. Xipeng Xiao, Alan Hannan, and Brook Bailey, Global Center Inc. Lionel M, NI, ichigan State University. Traffic Engineering with MPLS in the Internet. [8]. Rahman M.A.,Kabir A.H., Lutfullah K.A.M., Hassan M.Z. and Amin M.R., Performance analysis and the study of the behavior of MPLS protocols, International Conference on Computer and Communication Engineering ICCCE, May 2008, Page(s): [9]. Foundry networks white paper- IP/MPLS-Based VPNs, Layer-3 vs. Layer-2. [10]. Manor College, Empirical Research, What is Empirical Research, 2006.[Online].Available: mpiricalresearch.htm. [Accessed: 09-Oct-2010]. [11]. L. D. Ghein, MPLS Fundamentals. USA: Cisco Press, [12]. K. Jannu and R. Deekonda, OPNET simulation of voice over MPLS with consideringtraffic Engineering, BlekingeInstitue of Technology, [13]. R. Gallaher, MPLS Training Guide: Building Multi- Protocol Label SwitchingNetworks. Syngress Publishing, [14]. Shahid Ali Bilal ZahidRana, OPNET Analysis of VoIP over MPLS VPN with IP 143

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