1. MULTI-PROTOCOL LABEL SWITCHING By: By: YASHWANT.V YASHWANT.V ROLL NO:20 ROLL NO:20

2. CONTENTS Introduction Introduction Issues with routing Issues with routing What is MPLS….? What is MPLS….? How does MPLS work….? How does MPLS work….? MPLS Network MPLS Network Protocols Used Protocols Used Advantages Advantages Applications Applications

3. INTRODUCTION MPLS was originally proposed by a group of engineers from Ipsilon Networks, but their "IP Switching" technology, which was defined only to work over ATM, did not achieve market dominance. Cisco Systems, Inc. introduced a related proposal, not restricted to ATM transmission, called "Tag Switching" when it was a Cisco proprietary proposal, and was renamed "Label Switching" when it was handed over to the IETF for open standardization.

4. ISSUES WITH ROUTING Flexibility of routing Flexibility of routing Integration with established technologies Integration with established technologies Additional Services Additional Services Extensibility into new technologies Extensibility into new technologies

5. What is M P L S….? MPLS is based on the concept of label switching MPLS is based on the concept of label switching Operates at an OSI Model layer. Operates at an OSI Model layer. Referred as “Layer 2.5” protocol. Referred as “Layer 2.5” protocol. Designed to provide a unified data-carrying service for both circuit-based clients and packet-switching. Designed to provide a unified data-carrying service for both circuit-based clients and packet-switching. MPLS is a technology used for optimizing traffic forwarding through a network. MPLS is a technology used for optimizing traffic forwarding through a network. MPLS combines the best of both Layer 3 IP routing and Layer 2 switching. MPLS combines the best of both Layer 3 IP routing and Layer 2 switching.

6. How does M P L S work…? MPLS assigns labels to packets for transport across a network. MPLS assigns labels to packets for transport across a network. The labels are contained in an MPLS header inserted into the data packet. The labels are contained in an MPLS header inserted into the data packet. These short, fixed-length labels carry the information that tells each switching node (router) how to process and forward the packets, from source to destination. These short, fixed-length labels carry the information that tells each switching node (router) how to process and forward the packets, from source to destination. They have significance only on a local node-to-node connection. They have significance only on a local node-to-node connection. As each node forwards the packet, it swaps the current label for the appropriate label to route the packet to the next node. As each node forwards the packet, it swaps the current label for the appropriate label to route the packet to the next node.

7. ….contd ….contd MPLS networks establish Label-Switched Paths (LSP s) for data crossing the network. MPLS networks establish Label-Switched Paths (LSP s) for data crossing the network. LSP s direct packets in one of two ways: hop-by-hop routing or explicit routing. LSP s direct packets in one of two ways: hop-by-hop routing or explicit routing. Hop-by-hop routing: In hop-by-hop routing, each MPLS router independently selects the next hop for a given Forwarding Equivalency Class (FEC). A FEC describes a group of packets of the same type; all packets assigned to a FEC receive the same routing treatment. Hop-by-hop routing: In hop-by-hop routing, each MPLS router independently selects the next hop for a given Forwarding Equivalency Class (FEC). A FEC describes a group of packets of the same type; all packets assigned to a FEC receive the same routing treatment. Explicit routing: In explicit routing, the entire list of nodes traversed by the LSP is specified in advance. The path specified could be optimal or not, but is based on the overall view of the network topology and, potentially, on additional constraints. Explicit routing: In explicit routing, the entire list of nodes traversed by the LSP is specified in advance. The path specified could be optimal or not, but is based on the overall view of the network topology and, potentially, on additional constraints.

8. M P L S NETWORK

9. Data flow in an MPLS network PE routers first establish LSP s. PE routers first establish LSP s. Non-MPLS traffic is sent through its CE router Non-MPLS traffic is sent through its CE router PE router performs a lookup on information in the packet PE router performs a lookup on information in the packet P router swaps labels as per LIB P router swaps labels as per LIB At egress PE, the last MPLS is removed At egress PE, the last MPLS is removed The packet proceeds to the destination CE and into the customer's network. The packet proceeds to the destination CE and into the customer's network.

10. PROTOCOLS USED…. CR-LDP: Constraint-based Routing Label Distribution Protocol CR-LDP: Constraint-based Routing Label Distribution Protocol RSVP-TE :Resource Reservation Protocol Tunneling Extensions RSVP-TE :Resource Reservation Protocol Tunneling Extensions

11. ADVANTAGES MPLS enables a single converged network to support both new and legacy services MPLS enables a single converged network to support both new and legacy services MPLS enables traffic engineering. MPLS enables traffic engineering. MPLS supports the delivery of services with Quality of Service (QoS) guarantees. MPLS supports the delivery of services with Quality of Service (QoS) guarantees. MPLS reduces router processing requirements, since routers simply forward packets based on fixed labels. MPLS reduces router processing requirements, since routers simply forward packets based on fixed labels. MPLS provides the appropriate level of security MPLS provides the appropriate level of security MPLS VPNs scale better than customer-based VPNs MPLS VPNs scale better than customer-based VPNs

12. TRAFFIC ENGINEERING HYPER AGGREGATION PROBLEM HYPER AGGREGATION PROBLEM

13. APPLICATIONS Telecommunications traffic engineering. Telecommunications traffic engineering. M P L S Virtual Private Networks M P L S Virtual Private Networks

14. REFERENCES http://en.wikipedia.org http://en.wikipedia.org http://en.wikipedia.org http://ciscorouters.com http://ciscorouters.com http://ciscorouters.com http://mplsfaqs.org http://mplsfaqs.org http://mplsfaqs.org

15. “ T H A N K Y O U ” “ T H A N K Y O U ”