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In early 1997, the Internet Engineering Task Force (IETF) established the Multi-protocol Label Switching (MPLS) working group to produce a unified and interoperable multilayer switching standard as each vendor (Cisco Systems, Lucent, and so on) developed a proprietary multilayer switching solution, maintaining the IP control component and label-swapping components in different ways. The majority of these multilayer switching solutions required an ATM transport because they could not operate over mixed media infrastructures, such as Frame Relay, PPP, SONET, and LANs. Multi Protocol Label Switching (MPLS) is a versatile solution to address the problems faced by present day networks “ speed, scalability, Quality of Service (QoS) management, traffic engineering. MPLS performs a number of functions, such as, 1) it specifies mechanisms to manage traffic flows of various granularities, such as flows among different hardware, machines, or even flows among different applications. 2) It remains independent of the Layer 2 and Layer 3 protocols. 3) It provides a means to map IP addresses to simple, ixed-length labels used by different packet-forwarding and packet-switching technologies. 4) It interfaces to existing routing protocols such as Resource Reservation Protocol (RSVP) and Open Shortest Path First (OSPF). 5) It supports the IP, ATM, and frame-relay Layer 2 protocols. In this presentation, the concept of MPLS will be delivered

This article is presented by:
Gautham Pamu

MPLS Architecture

CS590F - Design of MultiService Networks





Goals of MPLS
Scalability of network layer routing.
Using labels as a means to aggregate forwarding information,while working in the presence of routing hierarchies.
Greater flexibility in delivering routing services.
Using labels to identify particular traffic which are to receive special services, e.G. QoS.
Increased performance.
Using the label-swapping paradigm to optimize network performance.




Goals of MPLS
Simplify integration of routers with cell switching based technologies.
Making cell switches behave as routers.
By making information about physical topology available to network layer routing procedures.




Motivation Behind MPLS

MPLS improves internet scalability by eliminating the need for each router and switch in a packet's path to perform traditionally redundant address lookups and route calculation.
Improves scalability through better traffic engineering.
MPLS also permits explicit backbone routing, which specifies in advance the hops that a packet will take across the network.
This should allow more deterministic, or predictable, performance that can be used to guarantee QoS.




Introduction to MPLS

These paths function at layer 3 or can even be mapped directly to layer 2 transport such as ATM or frame relay.
Explicit routing will give IP traffic a semblance of end-to-end connections over the backbone.
The MPLS definition of IP QoS parameters is limited.
Out of 32 bits total, an MPLS label reserves just three bits for specifying QoS.


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Presented By..
Namrata Pawar

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MultiProtocol Label Switching (MPLS)

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Introduction
Multiprotocol Label Switching (MPLS), is a mechanism in high-performance telecommunications networks which directs and carries data from one network node to the next with the help of labels. MPLS makes it easy to create "virtual links" between distant nodes. It can encapsulate packets of various network protocols.
MPLS Architecture
Labels
A label is short, fixed length physically continuous identifier which is used to identify a FEC ( forwarding equivalence class), usually of local significance.
FEC is a representation of group of labels that shares same requirements for their transport.
LSR’s
Label Switch Router-
An LSR is a high-speed router device in the core of an MPLS network that participates in the establishment of LSPs using the appropriate label signaling protocol and high-speed switching of the data traffic based on the established path.
Label Edge Router-
An LER is a device that operates at the edge of the access network and MPLS network. LER’s support multiple port connected to dissimilar networks(such as frame relay ,ATM, and Ethernet) and forward this traffic on the MPLS.
The Label Stack
Label stack carries a number of labels organized as a last-in, first out stack.
The processing is always based on the top label.
An unlabeled packet can be thought as a packet whose label stack is empty.
MPLS - The Motivation
IP Protocol Suite - the most predominant networking technology.
Voice & Data convergence on a single network infrastructure.
Continual increase in number of users.
Demand for higher connection speeds.
Increase in traffic volumes.
Ever-increasing number of ISP networks.
MPLS Traffic Engineering
MPLS Traffic Engineering (TE) provides high quality IP service.
TE is primary done by external tools. This solution allows flexibility and customization.
Applications of MPLS
Provide a mechanism to prioritize LSPs the case of resource contention.
Automatic bandwidth adjustment.
Provide precise control over how a path is rerouted in case of a single or multiple failures.
Hop by Hop Routed Traffic.
Explicitly Routed LSP.
reduce (not eliminate!) packet loss.
Multi-Path Routing.
MPLS Advantages
Simplified Forwarding
Efficient Explicit Routing
Traffic Engineering
QoS Routing
Mappings from IP Packet to Forwarding Equivalence Class (FEC)
Partitioning of Functionality
Common Operation over Packet and Cell media
MPLS - The Future
Who will use MPLS?
Large-scale data networks used by Enterprises, Carriers.
Why MPLS?
Provides Traffic Engineering - allows the user to direct traffic based on network utilization and demand.
Ease of provisioning QoS
Conclusion
MPLS will be an integral part of deploying the next generation network. It provides necessary bridges between IP and photonic dimensions MPLS protocol provides neighbor discovery and page link management. Link management protocol provides fault detection and restoration of the network. MPLS protocol provides high performance networks. MPLS mainly focus on control plane (the management of connection) rather than the data plane(actual data traffic).