Experiences with Deploying a Global IP/MPLS NetworkThomas TelkampDirector Data Architecture and TechnologyGlobal Crossing Telecommunications, Inc.telkamp@gblx.netChina International SummitTechnology Convergence &Next Generation NetworksSeptember 25 - 26, 2001Beijing, P.R. China

AgendaGlobal Crossing NetworkIP Network Evolution and PhilosophyMPLS DeploymentIP VPNsMulti-Service and DiffServNew FeaturesOther IssuesSummary

Global Crossing HistoryThe First Independent Global Fiber NetworkStarted operations in March 1997First segment in service on May 26, 1998Expanding Network and Services by acquisitions:Frontier Telecommunications, Sept 1999Racal Telecom, Nov 1999Hutchison Global Crossing, Jan 2000IXNET/IPC, June 2000Global Network100,000 route mile, 27 countries, 200 major cities

Cable ship...

and the cable.

Global IP Backbone Network

Global IP NetworkOC-48c/STM-16c (2.5Gbps) IP backboneSome 10Gbps segments operational (e.g. Atlantic)Multi-Vendor:Cisco GSR 12000/12400Juniper M20/M40/M160BGP and IS-IS routing protocolsInternet Access & Transit ServicesIP VPN, Layer 3 and Layer 2Global MPLS and DiffServ deployment

IP Network EvolutionNetwork technology and usage changes over time

RoadmapUS domestic backbone for Internet trafficMPLS deployment for Traffic EngineeringGlobal extension of the networkRFC2547 VPNsDiffServ deployment for multi-serviceOptimization for critical services (e.g. voice)

Network PhilosophyNo bottlenecks in normal conditionOverprovisioningwith use of Traffic Engineering network can handle all traffic, even when the most critical links fails

MPLS Traffic Engineering to prevent congestionDiffServ to manage congestion

Too complex and too many features will make the network unreliable/unstable

MPLS DeploymentOperational since 2Q 1999Traffic EngineeringIP TTL issues

Worldwide MPLS mesh 1Q 2001Currently over 6000 MPLS LSPs

Support for RFC2547 VPNsMPLS/BGP technology

MPLS LSP Deployment

MPLS Deployment Experiences and ChallengesRouter vendor interoperabilityCisco and JuniperNew features...Requires seamless networkSingle ASSingle IGP (no multiple areas/levels)NOC education and trainingNetwork ManagementSoftware to support Traffic Engineering

Why Traffic Engineering?

MPLS Traffic Engineering

IP VPNsRFC2547 VPNBased on existing MPLS and BGP protocols

Minimal impact on operations if already running a MPLS based Internet backbone

Layer 2 variant under development

DiffServ DeploymentIncrease revenue by value-added servicesBest-EffortInternetAssuredtrading and non-interactive audio and video)Real-timevoicePrefer higher classes during congestionmajor failuresguarantee delay and jitter

DiffServ ChallengesHow many classes?What are the targeted applications for each class?Can end users distinguish between classes?

How to implement these classes?Different queuing/scheduling mechanismsStrict Priority QueuingWRR/WFQand combinationsConfiguration and Monitoring issues...

New FeaturesMPLS Fast RerouteProvides SDH like restoration times for critical services (e.g. voice and trading)

Per-Class Traffic EngineeringAvoid concentration of real-time traffic at any linkSet upper limit on bandwidth reservations per class

IGP tuning for better performanceIS-IS parameters and configuration

Other Issues...What about GMPLS?What are the benefits to the IP layer?What problems does it solve?

Do we still need ATM?Cell based networks have different characteristics than packet based networksCBR service for Circuit Emulation

Should we build Pure IP networks?There are alternatives to MPLS Traffic Engineering and MPLS based VPNs

SummaryEvolve existing network or build new network based on applications and requirements:MPLS for Traffic EngineeringDiffServ for service differentiationAdvanced features for critical applications

Dont underestimate the operational aspects of new technology in the network

Too complex and too many features will make the network unreliable and unstable

Questions?