7/28/2019 Final Mp Ls Primer

1/3

A Guide to MPLS

Technology Overview

MPLS stands for "Multiprotocol Label Switching". In an MPLS network, incomingpackets are assigned a "label" by a "label edge router (LER)". Labels are a simpleindexing mechanism that replaces traditional IP packet forwarding, which is based on

complicated address matching algorithms with fast, simple ATM-like switching. At eachhop in the network, a router just examines a label to figure out the next forwarding hop

for the packet. This eliminates resource intensive address lookups that reduce overallpacket throughput and limit scalability.

Packets are forwarded along a "label switch path (LSP)", where each "label switch router(LSR)" makes forwarding decisions based solely on the contents of the label. At

each hop, the LSR strips off the existing label and applies a new label that tells the next

hop LSR how to forward the packet. Labels are distributed between LERs and LSRsusing a label distribution protocol (LDP). Switch routers in an MPLS network

regularly exchange label and reachability information with each other using standardizedprocedure in order to build a complete picture of the network they can then use to

forward packets.

Label Switch Paths (LSPs) are established by network operators for a variety of

purposes, such as to guarantee a certain level of performance, to route aroundnetwork congestion, or to create IP tunnels for network-based virtual private

networks. In many aspects, LSPs are no different than switched paths in ATM or FrameRelay networks, except that they are not dependent on a particular Layer 2 technology.

An LSP can be established that crosses multiple Layer 2 transport protocols such asATM, Frame Relay or Ethernet. Thus, one of the great values of MPLS is the

ability to create end-to-end connections, with specific performance characteristics, acrossany type of transport medium, eliminating the need for overlay networks andmultiple control mechanisms unique to each type of Layer 2 transport technology.

The same control mechanisms that make MPLS so useful in the packet domain are also

being extended to the optical domain with the development of GMPLS. These controlproperties enable optical cross connect nodes, such as Nortel Networks OPTera ConnectHDX optical switch, to switch wavelengths by dynamically signaling and creating light

paths on demand, reducing from months to seconds the amount of time required bynetwork operators to provision optical capacity. This powerful capability will underpin a

new generation of high performance services such as optical VPNs, storage areanetworks and bandwidth trading.

7/28/2019 Final Mp Ls Primer

2/3

2

First and next-generation MPLSFirst-generation MPLS enhanced the performance and scalability of IP networks by

replacing traditional IP packet forwarding that used complicated address matchingalgorithms with fast, simple ATM-like switching based upon labels. First-generation

MPLS solutions provide basic traffic engineering and virtual private network (VPN)

connectivity services. However, first-generation MPLS solutions fail to fully utilize thepotential of MPLS by not leveraging new developments in optical and wireless

technology.

Next-generation MPLS solutions are optimized for fast, profitable service creation andservice delivery across data, optical, wireless and voice networks using a flexiblenetworking architecture. They make new services possible and deliverable by these

networks. Next-generation MPLS delivers profitability, minimizing future capitalinvestment and reducing network operations expenses.

Nortel Networks forges ahead with next-generation MPLS solutionsNortel Networks is unique, offering an end-to-end portfolio that is MPLS enabled. Nortel

Networks offerings provide solutions that will drive profitability into service providernetworks. These solutions cover the five major MPLS networking product segments:

Optical Switch, Optical Ethernet, Multiservice Switch, IP Service Switch and MPLSRouter.

Nortel Networks next-generation MPLS:- Adds value to existing MPLS networks by enhancing their data services content

- Extends and expands returns on network infrastructure by providing seamlessevolution

- Fosters introduction of revolutionary, differentiated services, such as optical

VPNs, Optical Ethernet, optical storage networking and bandwidth-on-demand

- Shrinks optical service provisioning time from months to minutes- Reduces operations expense by simplifying both the network through integration

of multiple layers and network operations by integrating multiple networks- Protects margins through delivery of premium services, reliably and SLA penalty-

free

Key things Nortel Networks does with MPLS

Nortel Networks is pioneering MPLS contribution to optical networks by applyingMPLS concepts to enhance the intelligence of optical networks. Renowned for its

standards contributions in generalized MPLS (GMPLS) and the Automatically SwitchedTransport Network (ASTN), the emerging architectural standard for intelligent opticalnetworks. Nortel Networks has parlayed its work into a number of optical solutions that

provide the foundation for new optical services and alter optical network topology andprovisioning paradigms.

Nortel Networks MPLS bridges current multiservice networks to next-generationnetwork cores. Through MPLS incorporation, service providers can cost effectively

evolve their Layer 2 networks and market a new generation of carrier-grade, real-time

7/28/2019 Final Mp Ls Primer

3/3

3

services. Nortel Networks leverages its full-service VPN solutions to enhance thecapability and service functionality of MPLS networks.

Nortel Networks answers the challenge of migrating wireless networks to all-IP with its

practical plan to evolve ATM-based networks to IP/MPLS to an all-optical core. It

introduces a 3G core data network that is standards-based and MPLS-capable, in itsinitial 3G rollout. Nortel Networks 3G UMTS solution delivers robust QoS and advanced

traffic engineering essential for wireless real-time services. Nortel Networks plan takeseconomics to heart, averting high capital cost and service disruption resulting from

wholesale platform substitution.

Nortel Networks Solutions Unveiled

Nortel Networks preserves the utility of existing service provider infrastructure, byoffering MPLS gateway functionality on our Passport 7000 & 15000 Multiservice

Switches. Passport bridges traditional data networks to the MPLS network core. Thislinkage protects high-margin data service revenue streams, preserves current networkequipment and extends infrastructure investment returns.

Carriers can offer their customers massive optical capacity on demand, with fullycustomized service options with two Nortel Networks MPLS innovative solutions, the

OPTera Connect portfolio of optical switches and Nortel Networks Smart OpticalNetwork Solution.

Delay sensitive and high-priority guaranteed services, i.e., real-time services such asvoice or mission critical data services, can be delivered over MPLS controlled IP

networks with carrier-grade reliability today with Nortel Networks QoS-rich MPLSenabled Passport 7000 & 15000 Multiservice Switches.

The industry-leading Nortel Networks Shasta 5000 Broadband Service Node (BSN), asubscriber-edge IP Services switch will optimize the delivery of personalized value-

added services like VPN, security (stateful firewall, anti-spoofing) and QoS to MPLSnetworks.

Routing switches within core IP networks can be made scaleable from gigabits to multi-terabits using Nortel Networks state-of-the-art OPTera Packet Core . It aggregates flows

and switches at wire-speed under strict QoS control.

Attracting and retaining business customers becomes less daunting with a scalable,

standards-based virtual private Ethernet, Nortel Networks Optical Ethernet Solution.Optical An Optical Ethernet solution is a simpler more flexible approach for providing

value-added service to end-users.

* Nortel Networks, OPTera, Passport, Shasta and Shasta 5000 are trademarks of Nortel Networks. All other trademarks are the

property of their owners.

Copyright (C) 2001 Nortel Networks Corporation. All rights reserved. Information in this document is subject to change withoutnotice. Nortel Networks Corporation assumes no responsibility for any errors that may appear in this document.