MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp

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1 MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp MPLS and NGN Networks: The Future Aspects for Railways Communication System Alok Pandey E, E and I Department MIT, Moradabad, INDIA alok.pandey.eei@gmail.com Manas Singhal E and C Department MIT, Moradabad, INDIA manas.singhal.ec@gmail.com Manish Trikha E, E and I Department MIT, Moradabad, INDIA mainsh.trikha@gmail.com Mayank Kumar Goel Se. section Engineering Signal and telecom, Northern Railways mayankgoel1986@gmail.com ABSTRACT The objective of the project is to study the implementation of MPLS and NGN networks in Railways, and its future aspects for the railways communication system. The various aspects communication (of Core Network) has been studied and how we can implement by MPLS and NGN explained in this project report. Keywords: MPLS, NGN, Traditional IP. I. INTRODUCTION Drawbacks of Traditional IP Routing Basic MPLS Concepts MPLS Architecture MPLS Labels Label Switch Routers NGN Network addresses the packet by using the address of the destination node. The package is then sent onto the network, and finally, the network passes the packet to its destination. (i) Traditional IP forwarding is based on the following Routing protocols are used to distribute Layer 3(L3) routing information. Forwarding is based on the destination address only. Routing lookups are performed on every hop. Each router in the network makes an independent decision when forwarding packets. (ii) Drawbacks of Traditional IP Forwarding (Cont.) Traditional IP Forwarding LAN data transmissions fall into three classifications: unicast, multicast, and broadcast. In each type of transmission, a single packet is sent to one or more nodes. In a unicast transmission, a single packet is sent from the source to a destination on a network. First, the source node Figure 1: Shortest Path and Congestion

MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp. 15 20 16 2.2.2.2/32 DIRECT 0 0 10.0.1.0/30 DIRECT 0 0 10.0.1.2 Ethernet1/0 10.0.1.2/32 DIRECT 0 0 127.

2 MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp /32 DIRECT /30 DIRECT Ethernet1/ /32 DIRECT /8 DIRECT /32 DIRECT 0 0 Figure 2: LAN Transmission Methods A multicast transmission consists of a single data packet that is copied and sent to a specific subset of nodes on the network. First, the source node addresses the packet by using a multicast address. The packet is then sent into the network, which makes copies of the packet and sends a copy to each nodem that is part of the multicast address. A broadcast transmission consists of a single data packet that is copied and sent to all nodes on the network. In these types of transmissions, the source node addresses the packet by using the broadcast address. The packet is then sent on to the network, which makes copies of the packet and sends a copy to every node on the network. (iii) How to Generate Routing Table Static route A network administrator enters into the router Dynamic route A network routing protocol adjusts automatically for topology or traffic changese.g. RIP,OSPF,IS-IS,BGP (iv) The Routing Table Information <Router>display ip routing-table Routing Tables: Destination/Mask protocol pref Cost Nexthop Interface /0 STATIC /8 RIP /24 STATIC /32 OSPF 10 2 (v) Protocol Direct route discovered by the link-layer protocol. Static route configured manually. Route discovered by the dynamic routing protocol. For example: RIP, OSPF, IS-IS, BGP (vi) Route Preference The routers produced by different manufacturers have different specifications on the preferences of the routing protocols. Default value of Router series (VRP 5.1): Routing Protocol DIRECT OSPF IS-IS STATIC RIP IBGP OSPF ASE EBGP Untrustworthy (vii) Route Matching Fundamental Preference Longest matching Preference Cost (viii) Default Route The default route is also a static route. In brief, it is used when no matched route item can be found in the routing table. In the internet, 99.99% of the routers have a default route. It is not always the static route manually configured, Sometimes, the default route can be generated by the dynamic routing protocol. II. MPLS TECHNOLOGY MPLS: Multi-Protocol Label Switching Multi-Protocol Support multiple Layer-3 protocols, such as IP, IPv6, IPX, SNA

MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp. 15 20 17 Label Switching Label packets, and replace IP forwarding with label switching.

TYPICAL MPLS NETWORK Figure 4: Basic MPLS Concepts Figure 3: One MPLS Network with Multi-services MPLS helps reduce the number of routing lookups, possibly changes the forwarding criteria, and

3 MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp Label Switching Label packets, and replace IP forwarding with label switching. For more details about MPLS, refer to RFC 3031 (Multiprotocol Label Switching Architecture. III. TYPICAL MPLS NETWORK Figure 4: Basic MPLS Concepts Figure 3: One MPLS Network with Multi-services MPLS helps reduce the number of routing lookups, possibly changes the forwarding criteria, and eliminates the need to run a particular routing protocol on all the devices. Routers in a service provider network forward packets based on their destination addresses. All the routers need to run a routing protocol (BGP) to get all the Internet routing. Every router in the path performs a destination-based routing lookup in a large forwarding table (more than 10,000 routes). MPLS is a new forwarding mechanism in which packets are forwarded based on labels. Labels may correspond to IP destination networks (equal to traditional IP forwarding Labels can also correspond to other parameters (QoS, source address, etc.) MPLS was designed to support forwarding of other protocols as well. Only edge routers must perform a routing lookup. MPLS is the abbreviation of Multi-Protocol Label Switching. MP means it support more than one protocol, such as IP, IPv6, IPX, SNA, etc. as we know, in IP network, the routers forwarding packets by using packet s destination IP address and looking for the IP routing table to get the next hop, while in MPLS network, we using label to forward the packets, named label switching. MPLS uses a short label of fixed length to encapsulate packets. MPLS use FEC (Forwarding Equivalent Class) to classify the forwarding packets. The packets of the same FEC are treated the same in the MPLS network. later we will introduce the FEC. By adding a label to the packet at the entrance of MPLS network, the packet is forwarded by label switching, some thing like ATM Switching. And when leaving the MPLS network, the label added is removed and the label packet is restored to original protocol packet. Figure 5 LSR: Label Switch Router LER: Label Edge Router LSP: Label Switch Path Some basic concepts in MPLS: LSR is the basic component of the MPLS network. The network consisting of LSRs, is called an MPLS domain. The LSR located at the edge of the domain and having a neighbor not running MPLS is an edge LSR, also called Labeled Edge Router (LER). The LSR located inside the domain is called a core LSR. The core LSR can be either a router that supports MPLS or an ATM-LSR upgraded from an ATM switch. MPLS runs between LSRs in the domain, and IP runs between an LER and an router outside the domain. The LSRs along which labeled packets are transmitted form an LSP. IV. BASIC WORKING PROCESS OF MPLS The slide show the MPLS working process: 1. LDP establishes a label map for desired FECs in each LSR through the routing table generated by the traditional routing protocols like OSPF and IS-IS 2. The ingress receives a packet, determines its FEC and adds a label to the packet. This packet is called the MPLS labeled packet;

MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp. 15 20 18 3.

4. TTL: 8 bits, represents time to live, and has the same meaning as the TTL in the IP packet. VI. MPLS LABEL FORMAT Figure 8 Figure 6 MPLS is a tunnel technique rather than a service or application.

It supports multiple upper layer protocols and services, and guarantees security during the transmission of information. V.

4 MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp The Transits forward the packet according to its label and the label forwarding information base without any Layer 3 processing; 4. The egress rips off the label and continues forwarding for delivery. 4. TTL: 8 bits, represents time to live, and has the same meaning as the TTL in the IP packet. VI. MPLS LABEL FORMAT Figure 8 Figure 6 MPLS is a tunnel technique rather than a service or application. It is a routing and forwarding platform, combining the label switched forwarding with the network layer routing. It supports multiple upper layer protocols and services, and guarantees security during the transmission of information. V. MPLS ENCAPSULATION FORMAT AND LABEL A label is a short, fixed length, locally significant identifier which is used to identify a FEC. The label which is put on a particular packet represents the Forwarding Equivalence Class to which that packet is assigned. Figure 7 Most commonly, a packet is assigned to a FEC based (completely or partially) on its network layer destination address. However, the label is never an encoding of that address. A label contains four fields: 1. Label: 20 bits, represents label value, and used as the pointer for forwarding. 2. Exp: 3 bits, reserved, used for experiments, and generally used as Class of Service (CoS). 3. S: 1 bit, represents label stack. The value 1 refers to the bottom layer label. Just 0 means next head is MPLS header and 1 means next header is IP header. Field ID Length Purpose LABEL 20 bits Allocated for the actual label value EXP 3 bits MPLS experimental bits. A Cisco convention is to use these experimental bits as a means of representing the class of service (CoS) of the MPLS frame S 1 bit End-or-stack (EOS) bit. Some MPLS application such as L3MPLS VPNs require the use of multiple labels. The EOS is set on the last label in the stack of labels TTL 8 bits Time to live for the MPLS frame. This performs a similar function to an IPv4 TTL A label is a short, fixed length, locally significant identifier which is used to identify a FEC. The label which is put on a particular packet represents the Forwarding Equivalence Class to which that packet is assigned. Most commonly, a packet is assigned to a FEC based (completely or partially) on its network layer destination address. However, the label is never an encoding of that address. A label contains four fields: 1. Label: 20 bits, represents label value, and used as the pointer for forwarding. 2. Exp: 3 bits, reserved, used for experiments, and generally used as Class of Service (CoS). 3. S: 1 bit, represents label stack. The value 1 refers to the bottom layer label. Just 0 means next head is MPLS header and 1 means next header is IP header. 4. TTL: 8 bits, represents time to live, and has the same meaning as the TTL in the IP packet. VIII. DEMO-PRIVATE LABEL DISTRIBUTION Process steps 1. CE A2 send a update route item to PE-C with route protocol.

5 MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp Figure 9 2. PE-C received the update route item and store it in the corresponding VRF. 3. PE-C redistribute the VRF route into MP-BGP, add RD, change the next hop to itself, usually use the loopback address, add RT list and generate a private label for it. Via MP-BGP transmit the route item to all its neighbors. 4. The neighbor PE-A receive the route item and judge whether the received export is equal to the import of the local VRF. If yes, it will be added to the corresponding VRF routing table, and also the private label will be kept; otherwise, it will be discarded.5.pe-a corresponding VRF update the route item to CE A1 with route protocol. From CE A1 to CE A2, the process vice versa. 2. QOS enablement: One of the primary benefits of MPLS-based services is the ability to support QoS, particularly key for companies that are rolling out voice and video. 3. Improved performance: Because of the any-toany nature of MPLS services, network designers can reduce the number of hops between network points, which translates directly to increased response time and improved application performance. 4. Disaster recovery: MPLS-based services improve disaster recovery in a variety of ways. First and foremost, data centers and other key sites can be connected in multiple redundant ways to the cloud (and thus to other sites on the network). Secondly, remote sites can quickly and easily reconnect to backup locations if needed (unlike with ATM and frame networks, in which either switched or backup permanent-virtual-circuits are required). That s why several benchmark participants listed flexibility for business recovery as a key justifier behind their MPLS rollouts. 5. Future proofing the network: Most companies have come to the conclusion that MPLS represents the wave of the future. Investment in legacy WAN services (ATM, frame) has pretty much come to a standstill: Virtually no companies plan to invest in ATM or frame services within the next six to 12 months. As a result, companies increasingly say they re planning to migrate to MPLS primarily to avoid being left behind. VIII. DRAWBACKS IN MPLS Latency (100 ms): The finite amount of time it takes a packet to reach the receiving endpoint after being transmitted from the sending endpoint. Ping packet is an IP packet requesting that a copy of its contents be echoed back to the sender. When you ping a site, you send over an echo request and that site responds back that it received it. The amount of time it takes for the packet to get to that site, and then return to you, is the ping time, or Latency. Packet Loss (0.1%): A relative measure of the number of packets that were not received compared to the total number of packets transmitted. IX. TOP 5 REASONS TO MOVE TO MPLS 1. Cost savings: Depending on the specific mix of applications, and network configuration, MPLSbased services can reduce costs by 10% to 25% over comparable data services (frame relay and ATM). As companies add voice and video traffic, cost savings can rise to as much as 40% network wide. X. CASE OF LATENCY TRACEROUTE command in progress stlln :30:48 IST EAGLE Traceroute to clnknodastp1 ( ), 30 hops max, 100 byte packets 1 0 ms 0 ms 1 ms ( ) 2 1 ms 2 ms 1 ms ( ) 3 33 ms 50 ms 50 ms ( ) ms 170 ms 150 ms ( ) ms 177 ms 174 ms ( ) ms 55 ms 116 ms ( ) ms 117 ms 143 ms clnknodastp1 TRACEROUTE command complete. XI. NGN NETWORK ( ) Characteristics of an Ideal NetworkFusing the Best of Today s Networks and More.

CONCLUSION By the detailed study of MPLS we can conclude that it promises many features like improves packet

complexity of network operation which is very much required in our day to day life. REFERENCES [1] http://en.wikipedia.

6 MIT International Journal of Electrical and Instrumentation Engineering Vol. 3, No. 1, Jan. 2013, pp Figure 10 XII. CONCLUSION By the detailed study of MPLS we can conclude that it promises many features like improves packet forwarding performance in the network, Supports CoSandQoS for Service differentiation, improves network scalability, Integrates I.P and ATM in the network, Builds interoperable networks providing multi vendor interoperability, reduces the complexity of network operation which is very much required in our day to day life. REFERENCES [1] [2] [3] [4] [5] [6] [7] en.wikipedia.org/wiki/ngn [8]

Configuring MPLS and EoMPLS

Configuring MPLS and EoMPLS 37 CHAPTER This chapter describes how to configure multiprotocol label switching (MPLS) and Ethernet over MPLS (EoMPLS) on the Catalyst 3750 Metro switch. MPLS is a packet-switching technology that integrates