Table of Contents:

Definition and Overview

1. Introduction

2. MPLS Overview

3. A Technical Discussion of MPLS Traffic-Engineering Initiatives

4. Conclusion

Self-Test

Glossary

PDF of this tutorial

Definition
Multiprotocol label switching (MPLS) is one of several initiatives to enable delivery on the promise of a converged network. By combining the attributes of Layer-2 switching and Layer-3 routing into a single entity, MPLS provides the following benefits:

• enhanced scalability by way of switching technology
• class-of-service (CoS)– and quality-of-service (QoS)–based services (differentiated services)
• no need for an Internet protocol (IP)–over–asynchronous transfer mode (ATM) overlay model and its associated management overhead
• standards-based solution, promoting interoperability
• enhanced traffic-shaping and engineering capabilities

Overview
It is becoming increasingly apparent that the ability to reshape and engineer traffic dynamically to ensure timely prioritization and delivery has become paramount. Currently, there is an initiative to deliver traffic-engineering capabilities to MPLS. There are two distinct approaches that incorporate the obvious benefits traffic engineering provides to the network core. This tutorial examines the fundamental changes being made to signaling protocols used to manage data in a large MPLS network and make it possible to determine the best route, given a set of stated bandwidth constraints. The similarities and differences between Constrained-based Label Distribution Protocol (CR–LDP) and Traffic Engineering (TE)–ReSource ReserVation Protocol (RSVP) are discussed in detail.