MPLS( Multiprotocol Label Switching)

KHNOG

30 November, 2015

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Agenda •  Traditional IP Routing

•  MPLS Introduction

•  MPLS Features

•  MPLS Benefits

•  MPLS Terminology

•  MPLS: Control Plane

•  MPLS Data Plane

•  Forwarding Structures

•  MPLS Example

•  Question and Answer

What is MPLS?

•  It’s all about the Labels

•  Use the best of both words

- Layer 2

- Layer 3

•  Traditional IP Routing: The traditional IP

Routing where the packet forwarding discussion

are based on the IP address.

MPLS Features

•  MPLS forwarding based on the MPLS label.

MPLS Benefits

In modern routers, MPLS label switching is not much faster than IP routing, but MPLS is not used just because of its switching performance. There are several other benefits to MPLS:

•  MPLS decreases the forwarding overhead on the core routers.

•  MPLS supports the forwarding of non-IP protocols, because MPLS technologies are applicable to any network layer protocol.

•  MPLS supports multiple useful applications: - Unicast and multicast IP routing - VPN - TE - QoS - Any Transport over MPLS (AToM)

MPLS is very useful in service provider (and large enterprise) networks because it enhances BGP routing and provides different services and applications, such as Layer 2 and 3 VPNs, QoS, and TE.

MPLS Terminology

•  LSRs forward packets based on label and swap labels:

- The last LSR in the path also removes the label and forward the IP packets as normal IP Routing

•  Edge LSR:

- labels IP packet (impose label) and forwards them into the MPLS domain

- Forwards IP packets out of the MPLS domain

•  A sequence of labels to reach a destination is called an LSP

In an MPLS domain, there are two types of routes:

•  Label-Switched Router (LSR): A device that forward packets that are primarily based on labels

•  Edge LSR: A device that primarily labels packets or forwards IP packets out of an MPLS domain.

MPLS Control Plane

MPLS Data Plane

MPLS Forwarding Structures

MPLS Architecture Example

MPLS Packet Flow Basic Example