Branch-Based Network Architecture

Copyright © 1998, Cisco Systems, Inc. All rights reserved. Printed in USA.Presentation_ID.scr 1

114011026_05F9_c1 © 1999, Cisco Systems, Inc. 114011026_05F9_c1 © 1999, Cisco Systems, Inc.

2© 1999, Cisco Systems, Inc.

14011026_05F9_c1

Branch-Based NetworkBranch-Based NetworkArchitectureArchitecture

Session 1401Session 1401


314011026_05F9_c1 © 1999, Cisco Systems, Inc.

ObjectiveObjective

Provide the key factors todesign a cost-effective,branch-based network


AgendaAgenda

• Introduction

• Network Design

• Routing and Switching

• Scalability

• Security

• Management

• Examples

• Q&A



AgendaAgenda

• Introduction

• Network Design


• Scalability

• Security

• Management

• Examples

• Q&A


Some Typical CustomerSome Typical CustomerExamplesExamples

• Retail

• Financial

• Hospital

• Government



• Automatic tellermachines

• Transactions

• Branch alarmsystems

• E-mail

• Main branch callcenters

ATM (SDLC)

ATM (SDLC)

or

AlarmAlarm

Banking ExampleBanking Example

PBX


Application ExamplesApplication Examples

• Terminal emulation

• Enterprise Resource Planning (ERP)

• Transaction and DB (checking,transfers, ATM, and queries)

• Mail and file transfer

• Web integration

• Patient care



AsyncTerms

TerminalController

Modems

Mainframe

ClusterControl

Leased SDLCMultidrop

X.25 Usage BasedLocal Dial-Up

Async 12/2400Leased Bisync

Frame Relay, ISDNATM, SMDS, XDSL

FrameRelay

Technology EvolutionTechnology Evolution

TokenRing

37X5

Front EndProcessor

ClusterControl SDLC

Mainframe Mainframe

3745NPSI

X.25

X.25

PADPADPADPAD PADPAD

LocalLocalAccessAccess

GatewayGateway

3174ClusterControl

CIPServer

FrameRelay

SMDS

ATM

Client


Internet

OrderOrderLanguageLanguage

ConfigConfigLanguageLanguage

POTSISDNCable

ADSL

Wireless ATM

Mobile

FrameATMFUNI

Multiple AccessMultiple AccessTechnologiesTechnologies

ATM, FrameATM, FrameRelay, IP,Relay, IP,Voice ServicesVoice Services

Today’s Today’s MultiserviceMultiservice Networks Networks

D/CD/C D/CD/C

SDH/ATM/FR SDH/ATM/FR BackboneBackbone

Partner1



Network EvolutionNetwork Evolution

ApplicationApplicationResourceResourceControlsControls

SecuritySecurityControlsControls

ManageabilityManageabilityControlsControlsTransportTransport

ServicesServices

ApplicationsApplications

TransportTransportServicesServices

ApplicationsApplications


Hub

Multiplexer

Component ClassComponent Class

1

2

3

4

5

6

7NetworkNetwork

ApplicationApplicationServicesServices

TransportTransport

NetworkNetwork

Data LinkData Link

PhysicalPhysical StatStatMuxMux

Firewalls

Router

Bridge

Policy Servers

DNS/DHCP

LANSwitch

FR/ATMSwitch



Multiple Protocols Multiple Media

Ethernet

RoutersRouters

PrivatePrivate19.2, 56, 64 kbps

T1, E1, T3, E3

CircuitCircuitPOTS, BRI, PRI

Sw 56, H0, T1, T3

PacketPacketX.25, Frame Relay

SMDS, ATM

FDDI

TokenRing

IPIP

AppleTalkAppleTalk

ISDNISDN

SDLCSDLC

X.25X.25

NovellNovell

SRBSRB

XNSXNS

NetBIOSNetBIOS

DECnetDECnet

BanyanBanyan

FrameFrameRelayRelay

SMDSSMDS

OSIOSI


• Traffic generatedfrom a source to adestination

• Depending on theprotocol, trafficfrom source-destination-source maybe asymmetricor symmetric

Definition of a FlowDefinition of a Flow



• Application and networkbandwidth

• Batch and burst requirement

• Application packet size

• Application priority

• Latency

• Transactions/packetsper second

• Packet destination type:unicast, multicast orbroadcast

• Congestion behavior

• Data size and overhead

Boston256 Kbps Port

Dallas128 Kbps Port

Atlanta128 Kbps Port

New York512 Kbps Port

Know Your FlowsKnow Your Flows


Traffic Definition TypesTraffic Definition Types

• Unicast (one to one only)

• Multicast (one to many)

• Broadcast (one to all)



Data Is Replicated at the LastData Is Replicated at the LastPossible Point by the NetworkPossible Point by the Network

MulticastingMulticasting

• Saves bandwidth

• Permits simultaneous replication

• Offloads sending host

• Creates trees and branches

• Requires address management


Bandwidth(Kbps)

Quality

UnacceptableUnacceptableUnacceptable BusinessQuality

BusinessBusinessQualityQuality

TollQuality

TollTollQualityQuality

8

16

32

24

64

0

*PCM

**PCMPCM

*ADPCM 32 (G.723)

**ADPCM 32 (G.723)ADPCM 32 (G.723)

*ADPCM 24 (G.725)

**ADPCM 24 (G.725)ADPCM 24 (G.725)

*ADPCM 16 (G.726)

**ADPCM 16 (G.726)ADPCM 16 (G.726)

*LDCELP 16 (G.728)

**LDCELP 16 (G.728)LDCELP 16 (G.728)

*CS-ACELP 8 (G.729)

**CS-ACELP 8 (G.729)CS-ACELP 8 (G.729)

*LPC 4.8

**LPC 4.8LPC 4.8

(Cellular)(Cellular)(Cellular)

Application Example:Application Example:Voice CompressionVoice Compression



AgendaAgenda

• Introduction

•• Network DesignNetwork Design


• Scalability

• Security

• Management

• Examples

• Q&A


QosQosCompressionCompression

Tariff ManagementTariff ManagementBandwidth on DemandBandwidth on Demand

RedundancyRedundancyBackupBackup

Hierarchical DesignHierarchical Design

FirewallFirewallEncryptionEncryption

AuthenticationAuthentication

Network ManagementNetwork Management

Network Design CriteriaNetwork Design Criteria

• Bandwidth managementQoS, compression,bandwidth on demand,tariff management,capacity planning

• SecurityAuthentication, encryption,firewall

• High availabilityRedundancy, backup

• ScalabilityHierarchical design

• Manageability



Hierarchical Network DesignHierarchical Network Design

• Core

• Distribution

• Access

Best Way to Design for Scalabilityand Manageability


Core

Distribution

Access

Fully RedundantEfficient Traffic

Forwarding

Route SummarizationUse Separate Areas/

A.S. SAP FilteringEnable BW Features

Static or DefaultRoutes Compression

RegionalRegional

WAN CoreFR,ATM,

T3/E3,T1/E1

CentralCentral

RegionalRegionalRegionalRegional

BranchBranchBranchBranch



BranchBranchBranchBranch BranchBranch

BranchBranch

BranchBranch

SOHOSOHOSOHOSOHO

SOHOSOHOSOHOSOHO

SOHOSOHO

MobileMobileMobileMobile

MobileMobileMobileMobile

MobileMobile

WAN Hierarchical Logical DesignWAN Hierarchical Logical Design



• High speed for trafficforwarding

• Keep it simple, butredundant

• Not oversubscribed

• Don’t fullymesh—more complexand inefficient

CoreCore


• Access aggregation andoversubscription

• Address summarizationfor dedicated andbackup lines (ISDN,dial, etc.)

• Limit number of accesslines/PVCs per router

• Know your flows inorder to provisionbackbone uplinks andaccess links

• Bandwidth management

DistributionDistribution

Core

Distribution



• Bandwidthmanagement (QoS,compression

• Services

• Media encapsulationand conversion(X.25, STUN, SNA,

AccessAccess

Core

AccessATMATM


Topology DesignTopology Design

• Star topologies

• Fully-meshed topologies

• Partially-meshed topologies



• Advantages:

Simple managementand tariff costs

• Disadvantages:

Core router limitsperformance, singlepoint of failure andnot scalable

Start TopologiesStart Topologies


• Advantages:

High redundancy andsupports all netprotocols

• Disadvantages:

Large number of VCs,large number ofpacket/broadcastreplication

Fully-Meshed TopologiesFully-Meshed Topologies



• Combination of fulland star topology

•• Best mix to provideBest mix to providescalability, limitedscalability, limitednumber of VCs,number of VCs,redundancy andredundancy andperformanceperformance

Partially-Meshed TopologiesPartially-Meshed Topologies


Broadcast/Multicast IssuesBroadcast/Multicast Issues

• Multicast is treated as broadcast inpacket based nets

• Broadcast/multicast need to replicateover every VC on a physical line

• Different levels of broadcast withdifferent protocols

Broadcast/Multicast Scalability andBroadcast/Multicast Scalability andPerformance Will Vary Based onPerformance Will Vary Based onTopology and Media SelectionTopology and Media Selection



Leased LineLeased Line Frame RelayFrame Relay ATMATM

56kbps and56kbps andAboveAbove

OptimizesOptimizesSpeedSpeed

MinimizesMinimizesVariableVariable

PerformancePerformance

EasierEasierManagementManagement

Highest CostHighest Cost

56kbps to56kbps toT3/E3 kbpsT3/E3 kbps

VariableVariablePerformancePerformance

MoreMorePerformancePerformanceManagementManagement

Lowest CostLowest Cost

T1/E1 andT1/E1 andAboveAbove

BandwidthBandwidthFlexibilityFlexibility

Cell OverheadCell Overhead

CloudCloudRedundancyRedundancy

HighestHighestBandwidth/$Bandwidth/$

Some WANSome WANConnectivity OptionsConnectivity Options


The Internet Protocol (IP)The Internet Protocol (IP)



SNA, SNA, DECnetDECnet , AppleTalk…, AppleTalk…

• Legacy protocols

• Still have many applications inuse today

• Ships in the night or encapsulated inanother protocol (I.e., SNA over IP)

• All use bridging or proprietaryrouting protocols


Integrating Legacy into IPIntegrating Legacy into IP

• Permits legacy protocols onlywhere required

• Any to any host communication

• Reduces complexity of designand operations in the core anddistribution

• Uses efficient IP routing protocolsfor high availability

• Uses more cost-effective IP tools



AddressingAddressing

FDDI

FDDI

Network 1

Network 3

Network 2

Network 5

1.11.2

1.3

2.12.2

2.3

3.1

3.2

3.3

3.44.1

4.2

5.1

5.2

5.4

5.3

Network 4

TokenRing


Addressing IssuesAddressing Issues

• Efficient use of address space

• Growth

• Ease of administration

• Address efficiency vs. routingefficiency (summarization)

• Static vs. dynamic addressing

• Each routing/network protocol usesits own scheme (IP, IPX, DECnet)



Critical forCritical for Multiservice Multiservice Traffic Traffic

Queuing ComparisonQueuing Comparison

• FIFO queuing

• Weighted-fair queuing

• Priority queuing

• Custom queuing


AgendaAgenda

• Introduction

• Network Design

•• Routing and SwitchingRouting and Switching

• Security

• Scalability

• Management

• Examples

• Q&A



The BasicsThe BasicsRouting and SwitchingRouting and Switching

• What Is Routing?

• OSPF

• BGP

• What Is Switching?

• Packet Forwarding

• Layer 3 Switch


Router/Switch FunctionsRouter/Switch Functions

• Routing =building mapsand givingdirections

• Switching =moving packetsbetweeninterfaces



Routing Protocol GoalsRouting Protocol Goals

•• Optimal path selectionOptimal path selection

• Loop-free routing

• Fast convergence

• Limited design administration

• Minimize update traffic

• Scalable—support hierarchicaltopology

• Easy to configure


Routing Protocol ChoicesRouting Protocol Choices

• Static routes

• Dynamic

Internal Gateway Protocols(EIGRP, OSPF, RIPv1, RIPv2, etc.)

External Gateway Protocols (BGP4)

Multicast (PIM, DVMRP, mBGP)

• On-Demand Routing (ODR)



The Best for Designing a New Network,The Best for Designing a New Network,Requires a Hierarchical DesignRequires a Hierarchical Design

When to Use OSPFWhen to Use OSPF

• Required dynamic routing

• Hierarchical networks

• Address aggregation

• Fast convergence

• No periodic updates—efficientfor low-speed WANs


• Hub-spoke model

• Hub dynamicallymaintains routes

• No routing protocolrequired in stub

•• Works well whenWorks well whenonly limitedonly limitedaccess or non-access or non-dedicated linksdedicated links

On-Demand RoutingOn-Demand Routing

ODR

Dynamic Routing Protocol

PSTNISDN



AS 100 AS 101

AS 102

AA

Peering

DD

EE

BB

CC

BGP for External ConnectivityBGP for External Connectivity

• NOT an IGP, external gateway protocol

• Incremental update


When to Use BGPWhen to Use BGP

• Connecting to external entities owned oroperated by you (other AS)

• Only require connectivity information forbest optimal path decision

• Keeps internal routing informationseparate from external routing information

Use It when You Have Use It when You Have MultihomedMultihomedInternet or Partner ConnectionsInternet or Partner Connections



AgendaAgenda

• Introduction

• Network Design


•• ScalabilityScalability

• Security

• Management

• Examples

• Q&A


ScalabilityScalability

•• PerformancePerformance

• Growth and new applications

• Media costs

• Traffic flows and geographicconcentration

• Bandwidth efficiency

• Load distribution and balancing



Understanding Vendor ThresholdsUnderstanding Vendor Thresholds

•• Hardware and/or softwareHardware and/or softwarearchitectures and configurations varyarchitectures and configurations vary

• Often less than media speed for oneor more interfaces in network device

• Work with vendor to understandlimitations, threshold behavior, andtuning capabilities


High AvailabilityHigh Availability

• Understand application performanceand timeouts

• Queuing and flow control mechanisms(transport and application-based)

• Redundancy and load balancing issues(if possible to implement and how)

• Fast network convergence(level 2 or 3)



Scalability and RedundancyScalability and Redundancyfor Serversfor Servers

• Redundant servers (clusters)

• Traffic director (centralized)

• Distributed director (distributed)

• Content caching

• Replication and multicastingof contents


Application ScalabilityApplication Scalability

•• Know the applications and flowsKnow the applications and flows

•• TestTest with developers for LAN andWAN testing (Ethernet, Frame Relayand Dial)

•• TestTest redundancy and high availability

• Understand chatter



AgendaAgenda

• Introduction

• Network Design


• Scalability

•• SecuritySecurity

• Management

• Examples

• Q&A


Security IssuesSecurity Issues

• What is my corporate security policy?Traffic issues

Operational issues (network equipmentconfiguration and service denial)

What is your sensitive data?

What is your cost of loss of dataor service?

How do I verify my security policy?



Authenticated/Encrypted Tunnel

NAS

CustomerNetwork

HQNetwork

NetFlowCollector

ACLACL

ACLACL

ACLACL

Firewall

AAA Server

AAA Server

NMS

Authenticated/EncryptedConnection

Internet

SecuritySecurity


Network ConfigurationNetwork Configuration

• Password enabled or AAA forremote access and 16 levels ofadministrators

• Directory services

• Authentication for routing exchange

• Filtering authorized NOC stations

• Firewalling services and NOC

• Logging and reporting

• Active audits



AgendaAgenda

• Introduction

• Network Design


• Scalability

• Security

•• ManagementManagement

• Examples

• Q&A


AdministrationAdministration

• Configuration management

• Change management

• Inventory management

• Provisioning

• Policy management

• Capacity planning



OperationOperation

• Directory services

• Logging and data collection

• Availability management

• SLA monitoring and reporting

• Fault management


AgendaAgenda

• Introduction

• Network Design


• Scalability

• Security

• Management

•• ExamplesExamples

• Q&A



ExamplesExamples

• Banking

• Financial

• Retail


Banking ApplicationsBanking Applications

• Automatic teller machines

SDLC, bisync, security video

• Transactions

Deposits, wire, foreign exchange

• Branch alarm systems

• E-mail

• Main branch call centers



Banking RequirementsBanking Requirements

• Availability

• Security

• Multiprotocol

• QoS


Banking IP TransportBanking IP Transport

Voice/PBXVideoSDLC or BSCLAN

WAN Connect OptionsFrame Relay: Multi VCsLeased LineISDN (Backup)

IP PrecedenceIP Precedence

CARCAR

WREDWRED

CRTPCRTP

WFQWFQ CQCQ

ATM(SDLC)

ATM(BSC)

or

PBX

At Central SiteRedundant Routers (HSRP)VoIP Termination RouterISDN/Dial Backup

36403640

IP

3600

7200/7500

AlarmAlarm

ISDN/Dial



ATM, FR, Leased

Banking WAN SwitchedBanking WAN Switched

ATM(SDLC)

ATM(SDLC)

or Voice/PBXVideoSDLCLAN

WAN Connect OptionsMultiFlex Trunk: ATM ModeMultiFlex Trunk: ChannelizedSerial Port: Public FRSerial Port: LeasedSerial Port: PPP (No Voice)

Use ATM or Leased toInterconnect Multiple IGX Concentrators, UsingPublic FR Will Mean NoAutoRoute; up to 255Remote Connections per IGX 8400

IGX 8400

MC3810

AutoRouteAutoRoute

ForeSightForeSight

OptiClassOptiClass

ATM/FRATM/FR/Leased

AlarmAlarm

PBX


Financial: ApplicationsFinancial: Applications

• Stock trading—traditional

• Stock trading—Internet

• Stock ticker services (RT)

• Securities exchange

• Confirmations desk



Financial: RequirementsFinancial: Requirements

• Security

• Redundancy(high availability)

• Predictable and low delay

• Multicast

• High BW

• QoS to offer differentservice levels


Financial: DesignsFinancial: Designs

Home/RemoteTrading

Internet

Trading FloorForeignOffices

PBX

Branch

RedundantConnections

ConfirmationsDesk

NASDAQ 1999 +100 CSCO 99.9 +5 NASDAQ 1999 +100 CSCO 99.9 +5

Ticker Services

MulticastMulticast

BBFirewall

WebServers

AA HSRPHSRP

HSRPHSRP



Health Care: ApplicationsHealth Care: Applications

• Electronic medical recordsTextual/multimedia; capture, track,archive, retrieve

• TeleradiologyFilmless imaging system; capture, track,archive, retrieve

• Telemedicine (distant patient care)Remote diagnosis/surgery

Specialist to specialist consultation

• Continuing education


Health Care: RequirementsHealth Care: Requirements

• Security

• Bandwidth

• Redundancy

• QoS

RSVP, WFQ, IP precedence



Health Care: DesignsHealth Care: Designs

PBX

NurseCall Center

EMRServer

Admin/Finance

PhysicianOffice

Clinic

PartnerFacility

MRI Center

Home Health

PSTNISDN

StorageArray

Dry Process Print

Remote Clinic

RadiologistOffice

KidneyDialysisCenterIP PrecedenceIP Precedence

WFQWFQRSVPRSVP

CRTPCRTP

MAMAGNGN

ArchiveStation


RetailRetail

Regional Site or StoreRegional Site or StoreRedundant RoutersRedundant RoutersVoice Termination RouterVoice Termination RouterMultiple Computer Site Multiple Computer Site ConnectivityConnectivity

Store or OutletStore or OutletVoice/PBXVoice/PBXVideoVideoLANLAN

PBX

Central Site or Corp HQCentral Site or Corp HQRedundant Routers (HSRP)Redundant Routers (HSRP)Voice Termination RouterVoice Termination RouterHigh Speed BackupHigh Speed Backup

AlarmAlarm

Point of SaleLocal

DatabaseServer

ISDN/Dial

Backup SiteBackup SiteRedundant Routers (HSRP)Redundant Routers (HSRP)Voice Termination RouterVoice Termination RouterHigh Speed BackupHigh Speed Backup

WAN Connect OptionsWAN Connect OptionsFrame Relay, ATM, VPNFrame Relay, ATM, VPNLeased LineLeased LinePOTS or ISDN (Backup)POTS or ISDN (Backup)



AgendaAgenda

• Introduction

• Network Design


• Scalability

• Security

• Management

• Examples

•• Q&AQ&A


ReferencesReferences

• “Internetworking Design Basics” and“Designing Packet Services” on CCO

• Technology and products sessionsfor : WAN, Access, Cisco IOS,Security, Voice, NetworkManagement and General



ObjectiveObjective

Provide the key factors todesign a cost-effective,Branch-based network

76© 1999, Cisco Systems, Inc.

14011026_05F9_c1

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Branch-Based Network Architecture