Fast Reroute (FRR)  is very important factor of MPLS TE. If a link or a node fails in LSP of MPLSnetwork, FRR automatically reroutes traffic  i.e. switches traffic to the secondary path. For FRR, there are two paths; Primary path and Secondary or Backup path . Primary path is the main tunnel used to carry traffic. Secondary path is used to carry traffic if a node or a link fails in primary tunnel. FRR reduces the packet loss and restores the tunnel electric fast . The purpose of FRR is to reduce the packet loss and reroute the traffic as soon as possible. Though routing algorithm such is SPF algorithm can also recalculate new paths after the occurrence of a node or a link failure but this process is slow. It takes time for routing protocols to propagate link or node failure information across the network. Important traffic such as voice and video can’t wait for longer. They need a good QoS if not to drop packets.FRR provides protection against two types of failures .
cost of spare capacity point of view. Instead, a design that aims to minimize the congestion level during restoration is more acceptable under these circumstances. When applied to MPLS, the situation becomes quite different due to the application of the tunnelling mechanism. MPLS networks provide transport services through end-to-end tunnels for each demand node pair (O-D pairs for short). Note that these tunnels are also referred to as primary tunnels and set up as label switched paths. Meanwhile, backup tunnels coexist for survivability consideration. Unlike in pure IP networks where there is no means to separate the working and backup capacity, MPLS does have the capability to distinguish them by defining working and backup tunnels and designating corresponding capacity for each of them. The exploitation of the exact cost of spare or total capacity is allowed to be carried out. It is more beneficial to apply p-cycle based protection schemes for MPLS networks than for optical networks to some extent. MPLS functions over both the forwarding and control plane. It fundamentally is a Call Admission Control (CAC) mechanism because reservations are carried out on the control plane and take effect on the data plane only when traffic occurs. Therefore, it is instinctive to utilize the reserved but idle capacity, whereas in SONET or WDM networks, special operations are required in order to make use of idle spare capacity.
QOE (Quality of Experience) and QOS (Quality of Service) nomenclature are conventionally used interchangeably however are literally two separate conceptions. QOE is that the total system performance from the purport of read of the users. It’s the live of end-to-end performance at the accommodation level from the network user perspective and a designation of however well the system meets the user’s wants. Quality of Service (QOS) conjointly refers to a group of technologies (QOS mechanism) that transmute the network administrator to manage the results of congestion in integration as providing differentiated accommodation to cull networktraffic flows or to optate users. In order to distribute acceptable accommodation quality, QOS targets ought to be established for every accommodation and be enclosed ahead of time in system style and engineering processes. QOE for the tip utilizer is crucial and can be a key human with cognation to competitory accommodation offerings. Subscribers to network accommodations don’t care however accommodation quality is achieved. What matters to subscribers is however well an accommodation meets their goals and prospects their (QOE).To achieve this finish, the QOE engineering method involves the subsequent steps.
The IGP selected for operation in the service provider core was IS-IS. IS-IS was originally a protocol developed by Digital Equipment Corporation as part of DECnet and was standardized as ISO 10589. It was designed for usage on ISO’s Connectionless-mode Network Service or CLNS networks (ISO/IEC). IS-IS initially did not support the carrying of IP information, but was later extended to allow this ability (Digital Equipment Corporation). The updates in IS-IS allowed for it to be agnostic to the information it was carrying, and thus IS-IS is also able to carry IPv6 information. In contrast OSPF, the dynamic routing protocol native to IPv4, needed to be redesigned and rewritten as OSPFv3 to enable IPv6 functionality. IS-IS’s inherent extendibility also allows it to carry MPLStrafficengineering information internally, while OSPF needed to be extended to enable the same functionality using opaque LSAs (Katz, Kompella, & Yeung). With multiple revisions and extensions, to both protocols over the years, both protocols have the same features and functions available to them. Industry best practices are based on tried and tested principles where IS-IS is considered the choice protocol for large flat topologies (Bhattia).
ABSTRACT: Recently MPLS is used for building up VPNs in IP backbone, called MPLS VPN. To provide people with voice, data and all categories of multimedia services, distinguishing between data flows is a requirement. To address these router performance, Quality of Service and trafficengineering issues, Multi - Protocol Label Switching (MPLS) was proposed for IP based internetworks. To achieve the security that is required for corporate users, Virtual Private Networks (VPNs) can be used to guarantee that traffic is securely tunneled over the Internet. MPLS based VPNs enable connectionless routing within each VPN community. This paper discusses the benefits available in IP VPNs and how the MPLS+BGP model is selected in the network. Then how a branch office connects itself to other offices using MPLS VPN services delivered by a service provider.
For low number of packets generated by IP SLA and up to 50, both the TE and DS topologies show very low SD-latency (Source-to-destination latency) which is almost ideal. Starting from 100 and higher, both show exactly the same plot movement towards higher latency times but with different slopes. As expected, MPLS-TE generates around twice as much latency as QoS-DS. Usually, all the traffic load patterns of the network must be known to get the most out of MPLS-TE which usually auto-selects paths that may have better latency and more bandwidth. However, we are forcing both configurations to function on exactly the same path bringing into light their structural differences and raw capabilities. What is obvious here then is that TE is very sensitive to latency as it instantly fails when a lot of packets need to be transferred. QoS-TE‟ is different however as due to the fact that it is configured to manage VoIP packets, it recognizes that it is supposed to prioritize and transfer delay-sensitive packets which performance is easily affected by this delay. That explains why QoS-DS keeps delay times as low as possible which is consistently better than the conditions seen under MPLS-TE. Figure 8 shows the most visible difference DS-TE appears to offer throughout all our testing scenarios. It completely eliminates latency. This does not mean that DS-TE always has a similar behavior but, within the definitions and constraints of the testing scenario built around IP SLA UDP jitter simulation, it does.
to suboptimal use of available bandwidth between a pair of routers in the service provider network. Predominantly, the suboptimal paths are under-utilized in IP networks. To avoid packet drops due to inefficient use of available bandwidth and to provide better performance, TE is employed to steer some of the traffic destined to follow the optimal path to a suboptimal path to enable better bandwidth management and utilization between a pair of routers. TE, hence, relieves temporary congestion in the core of the network on the primary or optimal cost links. TE maps flows between two routers appropriately to enable efficient use of already available bandwidth in the core of the network. The key to implementing a scalable and efficient TE methodology in the core of the network is to gather information on the traffic patterns as they traverse the core of the network so that bandwidth guarantees can be established.
discovered, the P-SHIM6 can divert the context affected by the failure through the new path, using the corresponding locator pair. It is also possible to feed the P- SHIM6 with additional information that can be used for failure detection. In particular, the P-SHIM6 can be fed with BGP information from the different ISPs – note that the site does not inject any information into BGP. In this case, the P-SHIM6 would have access to routing information and could divert the communication through an alternative ISP in case of a failure without requiring the use of REAP (or limiting it). Considering that multihoming, and therefore SHIM6, is aimed to enhance fault tolerance capabilities, special care has been devoted to describe configurations that preserve established communications in the case that the P-SHIM6 fails.
LEO satellite networks are likely to play an important role in the future Internet. It has been identified in the literature that communications infrastructure of the future will be characterized by the seamless integration of IEO satellite networks with broadband networking techniques in order to support multimedia services and provide global coverage as well as different types of traffics to be heterogeneously distributed to the world population. Based on the above criteria, ATM satellite networks and other selected terrestrial networks have been critically analyzed and their characteristics compared. Our survey studies have shown that: (a) ATM satellite networks have the capabilities of MPLS-based trafficengineering, Hence, the current trends are to use ATM technology as the underlying infrastructure for the next generation of enterprise and Global-IP networks;(b) Competing companies worldwide are migrating to 3G wireless as fast as possible in various steps using them as building blocks for the deployment of the next generations of mobile networks; (c) The cable TV networks, although started as a video service provider, has moved to the business of Internet access, and often the telephone business;(d) Recently,mobile applications are becoming very important ,Internet-based applications are becoming adapted to cellular systems, I-mode and WAP communications services are being provided to people living in rural areas; (e) The emerging wireless LANs have provided large bandwidths of data up to 11 or 54 Mbps; (f) Of course IEEE 802.11 LANs are not everywhere, but as more businesses open up in cities and rural areas, organizations may decide to install base stations for their employers and customers;(g) At best , due to limited range of WLANS, rural area farmers may resort to dual-mode wireless devices that use 802.11 if they can pick up a signal and fall back to WAP if they cannot;( h) The problem of full integration and the rate at which large amount of information must be updated for both the terrestrial networks and constellations networks as well as throughput constraints that lies in the limited capacity of the earth-space air interface will benefit if a Multipurpose Label Switching technique is deployed.
Internet backbones and transit networks are often oper- ated by commercial service providers. ISPs that connect to these domains require commercial Service Level Agree- ments (SLAs). If dollar-costs are associated with usage, op- timisation techniques can be used to minimise operational costs. These techniques result in the choice of the most cost efficient path for given settings. A recent paper by Uhlig et al.  addresses the problem of intra-domain traffic en- gineering by using an evolutionary algorithm to find near optimal BGP filters that balance the load over several inter- faces. Another possible trafficengineering method is over- flow routing.
This paper focuses on application of Multiprotocol Label Switching (MPLS) as a viable scheme of controlling internet traffic for greater efficiency and reliability. Graphical Network Simulator (GNS3) is utilized in the design and simulation of three different IP network routing scenarios: a network utilizing Open Shortest Path First (OSPF), one implementing both OSPF and Multi-Protocol Layer Switching (MPLS) and a network employing OSPF, MPLS and MPLS-Engineering (MPLS-TE). Performance comparison of different cases of IP routing in these networks are determined via throughput time of packets that traverse the network. Time taken for packets to traverse MPLS implemented network is shorter than that of OSPF based network. For example, the throughput times of OSPF only network for three, four and five routers network are, respectively, 64 68and 44 ms, while the corresponding throughput times in MPLSnetwork are 56, 52 and 40 ms, respectively. In addition to that, the traffic in MPLS-TE network is easily routed through a pre-determined path without conflict, thus ensuring other internet traffics are shipped across the network un-hindered. It is shown that MPLSnetwork addresses the challenges of internet service traffic by reducing the throughput time and allowing prioritizing of packets as they traverse the network routers.
TrafficEngineering is the process of selecting network paths so the traffic patterns can be balanced across the various route choices. The use of LSPs in MPLS can help balance the traffic on network link event . It allows a network administrator to make the path deterministic and bypass the normal routed hop-by-hop paths. An administrator may elect to explicitly define the path between stations to ensure QoS or have the traffic follow a specified path to reduce traffic loading across certain hops. In other words, the network administrator can reduce congestion by forcing the frame to travel around the overloaded segments. Trafficengineering, then, enables an administrator to define a policy for forwarding frames rather than depending upon dynamic routing protocols ,Trafficengineering is similar to source-routing in that an explicit path is defined for the frame to travel, However, unlike source- routing, the hop-by-hop definition is not carried with every frame .
For each O-D pair k, only one BE demand pair is defined, which can be looked as the aggregation of multiple BE demands with the same O-D. Unlike EF traffic, we allow the traffic within a single BE demand to split arbitrarily across any number of candidate LSPs, therefore the aggregation of BE traffic would potentially improve the effectiveness of trafficengineering. However, we assume only one backup path will be used for traffic on the same working path. We assume that the BE traffic may not be fully restorable in case of link failure. BE traffic restoration level r, a value between [0,1], represents the proportion of BE traffic on each link that is being protected. The ability to set the restoration level of BE traffic and accordingly differentiate the resilience level provides a powerful tool to the service provider. It allows the ISP to clearly demonstrate the advantage of premium service based on EF class, and also allows the ISP to fine tune the redundancy level and total network cost.
The Multi-Protocol Label Switching (MPLS) framework is used in internet service provider (ISP) and as a backbone to Internet Protocol (IP) to provide guaranteed efficient bandwidth and Quality of Service (QoS) provisioning in the network. This project seeks to investigate the QoS using DiffServ mechanism over MPLS and then compare the network performance in legacy networks. As a result, better network performance is observed with the integration of DiffServ over MPLS. DiffServ over MPLS provide the capability of the microflow traffic for each class- type in an aggregated packet stream with a LSP. Traffic preemption and resource preemption are introduced in QoS over MPLS to demonstrate that the class of traffic can be classless if MPLS setup-priority and holding-priority are pre-determined at user defined level.
Trafficengineering in MPLS LSPs are determined using the head end LSR or referred by source-based routing. Headend LSR networks need the whole picture and information related to trafficengineering. The information required includes: bandwidth, TE metric, maximum bandwidth, maximum bandwidth reserveble, Unreserved maximum bandwidth and administrative group. There are two ways of doing trafficengineering, which is online or offline. Example of online algorithms is MIRA,,,.
Internet implements packet switching technology where all the packets are provided with IP addresses. The MTU size is 1500 bytes that carries all types of application data i.e. data; voice and video which is also termed as triple play technology. Certain problem in IP network are describe in later chapter however IP packet carrying data performance is efficient as compare to voice and video data. In an ISP IP network, the forwarded traffic performs the destination IP address lookup in the router to send the data to desire destination. Which means an external IP prefix exists in the routing table of every ISPnetwork router. Border Gateway Protocol (BGP) is responsible for both external internet and customer prefixes so every router of an ISPnetwork must depend upon BGP protocol. While MPLS perform packet forwarding through label lookup only associated with egress router. Thus the label contains information regarding the packet for every intermediate router in the network instead of core router present at ISPnetwork. Only MPLS edge router need to run BGP to perform destination IP address lookup to forward the packet in an ISP, IP network.
tributed to all MPLS enabled routers that are expected to forward data for a specific FEC (Forwarding Equivalent Class) and LSPs created. The MPLS architecture does not assume any single signaling protocol. The power of MPLS depends on its TE capabilities and the efficiency of control plane i.e. routing and signaling. The routing protocols are basically reused from the IP system. Con- sequently, the design of signaling protocols is something that brings new functionalities and thus is very important for general operation as well as for TE. In this way Con- straint based routed Label Switched Path CR-LSPs are used for TE in MPLS . Two protocols are used to set CR-LSPs in MPLS that are:
Multiprotocol Label Switching [MPLS] is a differentiated and scalable framework introduced by IETF, which uses the simple configuration & management to deliver end-to-end IP services.If MPLS recovery mechanism mechanisms are increasing in popularity because they can guarantee fast restoration and high QoS reassurance. Their main advantage is that their backup paths are established in advance, before a failure event takes place.If the Fault tolerance is the ability of system respond to respond the gracefully to an unexpected hardware or software failure.by using fault recovery technique we can make MPLSnetwork fault tolerant. If MPLS used in splitting policy to make load balancing and fast local restoration. Such mechanism it is critical to properly to determine the set of split ratios. As they determine in what way the traffic is routed across the network. If the split ratio is guarantee high performance under different traffic loads. MPLS recovery mechanism are increasing in reputation because they can assurance the fast restoration and high QoS reassurance. If the main advantage is that backup paths are conservative in advance, before failure of link event take places. If the most research focusing on they establish of primary and backup paths has focused on minimizing added capacity to require the backup paths in the network. Then it is called Spare Capacity Allocation(SCA)metric is less practical for network operator will have a fixed capacitated network and want to increase their proceeds.A preplanned path protection scheme with sufficient spare bandwidth is appropriate for real time fault reestablishment in multiprotocol label switching (MPLS) network. It is importance of the network is to reduce the amount of sparebandwidth to prevent dreadful conditions of network efficiency.
Abstract:- In last couple of years, area of internet traffic measurement has advanced enormously in the number of users connected, in the increase in user access speeds and in the appearance of network-hungry applications. These changes greatly affected the work of Internet Service Providers and network administrators, which have to deal with increasing network users and capacity demands and abrupt traffic changes caused by new applications. The trafficengineering  is a method of optimizing the performance of a telecommunication network by dynamically analysing, predicting and regulating the link utilization over the network. The main objective of trafficengineering is to avoid congestion in the network and to make good use of available resources by controlling and optimising the routing, handles the unexpected traffic dynamics for achieving better quality of service. The connection-oriented approach uses signalling and is being used by techniques like Multi Protocol Label Switching (MPLS). Connection-oriented techniques offer a convenient way to monitor, allocate, reroute, and protect resources for a given traffic on an explicit and flexible basis. This survey explains the short overview about MPLSnetworktrafficengineering and future challenges of MPLS in future internet traffic control.
On the other hand, as the Internet is required to support different types of services, effective and efficient bandwidth management tools in IP networks becomes increasingly important, especially when dealing with how to allocate the available network resources in order to optimize the overall performance of the networks. And yet, when the network has to sustain heavy traffic load, and has limited resources, the situation of having some congested links, while others remain underutilized is almost an inevitable phenomenon . One of the main reasons to cause such congestion events in IP networks is that of the destination based forwarding paradigm.