Revised Spring 2006 Rudimentary NMS Software Components 1 The Network Management Problem Chapter 3 Network Management, MIBs, and MPLS Stephen B. Morris

Revised Spring 2006Revised Spring 2006 Rudimentary NMS Software ComRudimentary NMS Software Componentsponents

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The Network Management The Network Management ProblemProblem

Chapter 3Chapter 3

Network Management, MIBs, and MPLSNetwork Management, MIBs, and MPLS

Stephen B. MorrisStephen B. Morris

Rodrigo Iglesias de Aliaga


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OverviewOverview

Network Operators problems with the growth of Network Operators problems with the growth of traffic types and volumes.traffic types and volumes.

Operational increase due to Multiple NMS growth.Operational increase due to Multiple NMS growth. There is a strong need to reduce the cost of There is a strong need to reduce the cost of

ownership and improve the return on investment ownership and improve the return on investment (ROI) for network equipment.(ROI) for network equipment.


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OverviewOverview

Automated, flow-through actions are required for Automated, flow-through actions are required for network management operations.network management operations. ProvisioningProvisioning Detecting faultsDetecting faults Checking (and verifying) performanceChecking (and verifying) performance Billing/accountingBilling/accounting Initiating repairs or network upgradesInitiating repairs or network upgrades Maintaining the network inventoryMaintaining the network inventory


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Bringing the Managed Data to the Bringing the Managed Data to the CodeCode

Managed objects reside on many SNMP agent Managed objects reside on many SNMP agent hosts.hosts.

Copies of managed objects reside on SNMP Copies of managed objects reside on SNMP management systems.management systems.

Changes in agent data may have to be regularly Changes in agent data may have to be regularly reconciled with the management system copy.reconciled with the management system copy.


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Components of an NMSComponents of an NMS


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The Quality of an NMS is inversely proportional to The Quality of an NMS is inversely proportional to the gap between its picture of the network and the gap between its picture of the network and the actual state of the underlying network- the the actual state of the underlying network- the smaller the gap, the better the NMS.smaller the gap, the better the NMS.

As managed NES become more complex, an extra As managed NES become more complex, an extra burden is placed on the management system.burden is placed on the management system.


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ScalabilityScalability

Today’s Network is Tomorrow’s NEToday’s Network is Tomorrow’s NE Scalability is one of the biggest problems facing modern Scalability is one of the biggest problems facing modern

networking.networking. A scalability problem occurs when an increase in the A scalability problem occurs when an increase in the

number of instances of a given managed object in the number of instances of a given managed object in the network necessitates a compensating, proportional network necessitates a compensating, proportional resource increase inside the management system.resource increase inside the management system.


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Layer 2 VPN ScalabilityLayer 2 VPN Scalability

Scalability Problems tend to arise in situations of Scalability Problems tend to arise in situations of proportional growth.proportional growth.

The NThe N22 Problem Problem When the number of layer 2 virtual circuits required is When the number of layer 2 virtual circuits required is

proportional to the square of the number of sites.proportional to the square of the number of sites. Anything in networking that grows at the rate of NAnything in networking that grows at the rate of N22

tends to give rise to a problem of scale.tends to give rise to a problem of scale. As the number of sites gets bigger, the NAs the number of sites gets bigger, the N22 term is more term is more

significant than the other terms.significant than the other terms.


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The NThe N22 problem problem


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The NThe N22 problem problem

Layer 3 VPNsLayer 3 VPNs Layer 3 VPNs provide a much more scalable solution Layer 3 VPNs provide a much more scalable solution

because the number of connections required is because the number of connections required is proportional to a number of sites, not the square of the proportional to a number of sites, not the square of the number of sites.number of sites.

Layer 3 VPNs avoid the need for a full mesh between all Layer 3 VPNs avoid the need for a full mesh between all of the customer edge routers by providing these of the customer edge routers by providing these features:features:

A layer 3 coreA layer 3 core Overlapping IP address range across the connected sites (if Overlapping IP address range across the connected sites (if

separate organizations use the same VPN service)separate organizations use the same VPN service) Multiple routing table instances in the provider edge Multiple routing table instances in the provider edge

routersrouters


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Virtual Circuit Status MonitoringVirtual Circuit Status Monitoring

Scalability problems arise when the MIB table Scalability problems arise when the MIB table entries become very large due to NMS attempts entries become very large due to NMS attempts to read all MIB table entries at the same time.to read all MIB table entries at the same time.


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MIB ScalabilityMIB Scalability

Network operators and their users demand more:Network operators and their users demand more: BandwidthBandwidth Faster NetworksFaster Networks Bigger DevicesBigger Devices

Scalability concerns are growing because routers Scalability concerns are growing because routers and switches are routinely expected to support and switches are routinely expected to support the creation of millions of virtual circuits.the creation of millions of virtual circuits.


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Creating LSPs in an MPLS networkCreating LSPs in an MPLS network


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Other Enterprise Network Other Enterprise Network Scalability IssuesScalability Issues

Scalability concerns also affect enterprise Scalability concerns also affect enterprise networks in these areas:networks in these areas: Storage SolutionsStorage Solutions

Adding, deleting, modifying, and monitoring SANsAdding, deleting, modifying, and monitoring SANs Administration of FirewallsAdministration of Firewalls

Rules for permitting or blocking packet transitRules for permitting or blocking packet transit RoutersRouters

Access control lists and static routesAccess control lists and static routes Security ManagementsSecurity Managements

Encryption keys, biometrics facilities, and password controlEncryption keys, biometrics facilities, and password control Application ManagementApplication Management


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Light Reading TrialsLight Reading Trials

Internet core routers from Cisco, Juniper, Internet core routers from Cisco, Juniper, Charlotte’s Networks, and Foundry Networks were Charlotte’s Networks, and Foundry Networks were stress-tested during 2001 using these testsstress-tested during 2001 using these tests MPLS throughputMPLS throughput LatencyLatency IP throughput at OC-48IP throughput at OC-48 IP throughput at OC-192IP throughput at OC-192


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Large NEsLarge NEs

Advantages of the deployment of much bigger Advantages of the deployment of much bigger devicedevice They reduce the number of devices required, saving They reduce the number of devices required, saving

central office (CO) space and reducing cooling and power central office (CO) space and reducing cooling and power requirements.requirements.

They may help to reduce cabling by aggregating links.They may help to reduce cabling by aggregating links. They offer richer feature set.They offer richer feature set.

DisadvantagesDisadvantages They are harder to manage.They are harder to manage. They potentially generate vast amounts of management They potentially generate vast amounts of management

data.data. They are a possible single point of failure if not back up.They are a possible single point of failure if not back up.


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Expensive (and Scarce) Expensive (and Scarce) Development Skill SetsDevelopment Skill Sets

Building management systems for the devices of Building management systems for the devices of today and tomorrow is increasingly difficult.today and tomorrow is increasingly difficult.

General migration to a Layer 3 infrastructure is General migration to a Layer 3 infrastructure is another reason for the widening gap between another reason for the widening gap between available development skills and required product available development skills and required product features.features.

The need for customers to see rapid ROI for all The need for customers to see rapid ROI for all infrastructural purchasesinfrastructural purchases


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Expensive (and Scarce) Expensive (and Scarce) Development Skill SetsDevelopment Skill Sets

A different approach is needed for developing A different approach is needed for developing management systems.management systems.

Acquiring skills like these would positively Acquiring skills like these would positively enhance the development process.enhance the development process. A solution mindsetA solution mindset Distributed, creative problem solvingDistributed, creative problem solving Taking ownershipTaking ownership Acquiring domain expertiseAcquiring domain expertise Embracing short development cyclesEmbracing short development cycles Minimizing code changesMinimizing code changes Strong testing capabilityStrong testing capability


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A Solution MindsetA Solution Mindset

Solutions have a number of characteristicsSolutions have a number of characteristics Clear economic valueClear economic value Fulfillment of important requirementsFulfillment of important requirements Resolution of one or more end-user problemsResolution of one or more end-user problems


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A Solution MindsetA Solution Mindset


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Distributed, Creative Problem Distributed, Creative Problem SolvingSolving

Software BugsSoftware Bugs NE Bugs (Hard to identify)NE Bugs (Hard to identify) Performance Bottlenecks in FCAPS applications Performance Bottlenecks in FCAPS applications

due to congestion on the network.due to congestion on the network. Client Applications crashing from time to timeClient Applications crashing from time to time MIB Table CorruptionMIB Table Corruption SNMP Agent ExceptionsSNMP Agent Exceptions


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Distributed, Creative Problem Distributed, Creative Problem SolvingSolving

Tools available to solve these problemsTools available to solve these problems UML support packagesUML support packages Java/C++/SDL productsJava/C++/SDL products Version controlVersion control DebuggersDebuggers


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Taking OwnershipTaking Ownership

A broad task can be ring-fenced by a small group A broad task can be ring-fenced by a small group of developers who take responsibility for design, of developers who take responsibility for design, development, and delivery.development, and delivery.

Traditional development boundaries are removed.Traditional development boundaries are removed. No more pure GUI, backend, or database developers.No more pure GUI, backend, or database developers.

All NMS software developers should strive to All NMS software developers should strive to extend their portfolio of skills to achieve this.extend their portfolio of skills to achieve this.

Institutional memory relates to individual Institutional memory relates to individual developers with key knowledge of product developers with key knowledge of product infrastructure.infrastructure.


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Acquiring Domain ExpertiseAcquiring Domain Expertise

Domain expertise represents a range of detailed Domain expertise represents a range of detailed knowledgeknowledge IP/MPLS that can be readily applied to the needs of an IP/MPLS that can be readily applied to the needs of an

organization.organization.


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Acquiring Domain ExpertiseAcquiring Domain Expertise

Knowledge include areas such us:Knowledge include areas such us: Layer 2 and layer 3 traffic engineeringLayer 2 and layer 3 traffic engineering Layer 2 and layer 3 QoSLayer 2 and layer 3 QoS Network ManagementNetwork Management Convergence of legacy technologies into IPConvergence of legacy technologies into IP Backward and forward compatibility of new technologiesBackward and forward compatibility of new technologies

MPLSMPLS


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Linked OverviewsLinked Overviews

ATM Linked OverviewATM Linked Overview IP Linked OverviewIP Linked Overview Embracing Short Development CyclesEmbracing Short Development Cycles Minimizing Code ChangesMinimizing Code Changes


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Elements of NMS DevelopmentElements of NMS Development

NMS DevelopmentsNMS Developments Using a browser-based GUIUsing a browser-based GUI Developer wants to check that the software executed Developer wants to check that the software executed

the correct actionsthe correct actions During provisioning, developer verifies JavaDuring provisioning, developer verifies Java Database is updated by the management system codeDatabase is updated by the management system code Verifying that the correct set of managed objects was Verifying that the correct set of managed objects was

written to the NEwritten to the NE


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Elements of NMS DevelopmentElements of NMS Development

Data AnalysisData Analysis Upgrade considerationsUpgrade considerations UML, Java, and Object-Oriented DevelopmentUML, Java, and Object-Oriented Development Class Design for Major NMS FeaturesClass Design for Major NMS Features GUI DevelopmentGUI Development Middleware Using CORBA-Based ProductsMiddleware Using CORBA-Based Products Insulating Applications from Low-Level CodeInsulating Applications from Low-Level Code


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Expensive (and Scarce) Expensive (and Scarce) Operational Skill SetsOperational Skill Sets

The growing complexity of networks is pointing to The growing complexity of networks is pointing to increasingly scarce operational skillsincreasingly scarce operational skills

Multiservice SwitchesMultiservice Switches Enterprise network typically want to:Enterprise network typically want to:

Reduce the payback period for new purchasesReduce the payback period for new purchases Maintain and expand existing network servicesMaintain and expand existing network services Reduce operational costs associated with multiple networksReduce operational costs associated with multiple networks

TelephonyTelephony LANLAN


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Expensive (and Scarce) Expensive (and Scarce) Operational Skill SetsOperational Skill Sets

Multiservice SwitchesMultiservice Switches MPLS provides a way of filling these needs in conjunction MPLS provides a way of filling these needs in conjunction

with multiservice switcheswith multiservice switches ATMATM FRFR TDMTDM IPIP


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MPLS: Second ChunkMPLS: Second Chunk

Managed objects of MPLSManaged objects of MPLS Explicit Route ObjectsExplicit Route Objects Resource blocksResource blocks Tunnels and LSPsTunnels and LSPs In-segmentsIn-segments Out-segmentsOut-segments Cross-connectsCross-connects Routing ProtocolsRouting Protocols Signaling ProtocolsSignaling Protocols Label operationsLabel operations Traffic Engineering Traffic Engineering QoSQoS


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Explicit Route ObjectsExplicit Route Objects

An ERO is a of layer 3 address hops inside an An ERO is a of layer 3 address hops inside an MPLS cloudMPLS cloud

Describes a list of MPLS nodes through which a Describes a list of MPLS nodes through which a tunnel passes.tunnel passes.

EROs are used by signaling protocols to create EROs are used by signaling protocols to create tunnelstunnels


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Resource BlocksResource Blocks

MPLS permits the reservation of resources in the MPLS permits the reservation of resources in the network.network.

Resource blocks provide a means for recording Resource blocks provide a means for recording the bandwidth settingsthe bandwidth settings

Resource blocks includeResource blocks include Maximum reserved bandwidthMaximum reserved bandwidth Maximum traffic burst sizeMaximum traffic burst size Packet lengthPacket length


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Tunnels and LSPsTunnels and LSPs

MPLS-encapsulated packets enter the tunnel, MPLS-encapsulated packets enter the tunnel, pass across the appropiaye path, and exhibit pass across the appropiaye path, and exhibit three important characteristicsthree important characteristics Forwarding is based on MPLS label rather than IP headerForwarding is based on MPLS label rather than IP header Resource usage is fixed, based on those rederved at the Resource usage is fixed, based on those rederved at the

time of connection creationtime of connection creation The path taken by the traffic is constrained by the path The path taken by the traffic is constrained by the path

chosen in advance by the user.chosen in advance by the user.


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In-Segments and Out-SegmentsIn-Segments and Out-Segments

In-segments on an MPLS node represent the point In-segments on an MPLS node represent the point of ingress for trafficof ingress for traffic

Out-segments represent the point of egress for Out-segments represent the point of egress for traffictraffic


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Cross-ConnectsCross-Connects

MPLS node uses the cross-connect settings to MPLS node uses the cross-connect settings to decide how to switch traffic between the decide how to switch traffic between the segmentssegments

Connection TypesConnection Types Point-to-PointPoint-to-Point Point-to-MultipointPoint-to-Multipoint Multipoint-to-PointMultipoint-to-Point


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Routing ProtocolsRouting Protocols

MPLS incorporates standard IP routing protocols MPLS incorporates standard IP routing protocols such as OSPF, IS-IS and BGP4such as OSPF, IS-IS and BGP4


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Signaling ProtocolsSignaling Protocols

LSPs and tunnels can be achieved either LSPs and tunnels can be achieved either manually or via signalingmanually or via signaling

Signaled connections haveSignaled connections have Resource ReservedResource Reserved Labels DistributedLabels Distributed Paths selected by protocolsPaths selected by protocols

RSVP-TERSVP-TE LDPLDP


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Label OperationsLabel Operations

MPLS-labeled traffic is forwarded based on its MPLS-labeled traffic is forwarded based on its encapsulated valueencapsulated value

The operations that can be executed against The operations that can be executed against labels arelabels are LookupLookup SwapSwap PopPop PushPush


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MPLS EncapsulationMPLS Encapsulation

The MPLS Encapsulation specifies four reserved The MPLS Encapsulation specifies four reserved label valueslabel values 0-IPv4 explicit null that signals the receiving node to pop 0-IPv4 explicit null that signals the receiving node to pop

the label and execute an IP lookupthe label and execute an IP lookup 1-Router alert that indicates to the receiving node to 1-Router alert that indicates to the receiving node to

examine the packet more closely (rather than simply examine the packet more closely (rather than simply forwarding it)forwarding it)

2-IPv6 explicit null2-IPv6 explicit null 3-Implicit null that signals the receiving node to pop the 3-Implicit null that signals the receiving node to pop the

label and execute an IP lookuplabel and execute an IP lookup


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Qos and Traffic EngineeringQos and Traffic Engineering

LAN Bandwidth can be increased as needed using LAN Bandwidth can be increased as needed using switchesswitches Excess bandwidth helps avoid congestionExcess bandwidth helps avoid congestion

Traffic Engineering is set to become a mandatory Traffic Engineering is set to become a mandatory element of converged layer 3 enterprise element of converged layer 3 enterprise networks.networks.


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QoSQoS

There are three approaches that can be adopted There are three approaches that can be adopted for providing different levels of network servicefor providing different levels of network service Best effort (as provided by the Internet)Best effort (as provided by the Internet) Fine granularity QoS (Integrated Services – IntServ)Fine granularity QoS (Integrated Services – IntServ) Coarse granularity QoS (Differentiated Services – Coarse granularity QoS (Differentiated Services –

DiffServ)DiffServ)


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IP HeaderIP Header


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MPLS and ScalabilityMPLS and Scalability

This table can include millions of rowsThis table can include millions of rows It is not practical to try to read or write an object It is not practical to try to read or write an object

of this size using SNMPof this size using SNMP Unfortunately, it might be necessary if a network Unfortunately, it might be necessary if a network

is being initially commissioned or rebalanced is being initially commissioned or rebalanced after adding new hardwareafter adding new hardware


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SummarySummary

Bringing managed data and code together is one Bringing managed data and code together is one of the central foundations of computing and of the central foundations of computing and network managementnetwork management

Designers of management systems need rarified Designers of management systems need rarified skills set that matches the range of technologies skills set that matches the range of technologies embedded in NEs and networks Liberal use of embedded in NEs and networks Liberal use of standards documents and linked overviews are standards documents and linked overviews are some important tools for tackling the complexity some important tools for tackling the complexity of system development, managed object of system development, managed object derivation, and definition.derivation, and definition.

Networks must increasingly support a growing Networks must increasingly support a growing range of traffic types. (Traffic Engineering and range of traffic types. (Traffic Engineering and QoS handling in Layer 2 and Layer 3 Networks).QoS handling in Layer 2 and Layer 3 Networks).

Documents

Revised Spring 2006 Rudimentary NMS Software Components 1 The Network Management Problem Chapter 3 Network Management, MIBs, and MPLS Stephen B. Morris