Chapter Four: Solving the Network Management Problem

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Chapter FourSolving the Network Management
Problem

• Eleni Hailu

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The solutions include

• Filing the Development skills gap
• Smarter NMs
• Smarter MIBs
• Smarter NEs
• One data Model
• Distributed Server
• Policy-based Network Management
• Directory Enabled Networking

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Filing the development Skills gap

• Managing any given technology resolves down
  to the associated managed objects and management
  software.
• In Solution Engineering, the overall focus is not
  on a single item of work rather a combination of
  all the following components
• A complete GUI feature consisting of one or more
  screen pages
• The provisioning code for a feature such as IP
  traffic engineering
• A topology backend combined with fault management
• Performance monitoring software

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Filling

• Adding special-purpose NMs software
  infrastructure is particularly useful when
  software problems occur on used sites.
• The user can generate trace files and email them
  back to the developers for analysis and the
  developers can dial into the site and generate
  the trace files themselves.
• This helps avoid the need for developers to
  travel and can result in fast problem
  identification and accurate resolution.

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Filing

• There are many ways of adopting a solution
  engineering such as
• Web Browsing
• Virus Detection
• Document Processing
• Software Development

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Filing.

• Identifying and learning the constituent
  components usefully leverage the intellectual
  property freely available with GUI-based
  applications. This is beneficial because many of
  the components have become standard desktop
  objects such as
• Pull-down menus
• Dialog boxes
• Toolbars
• Icons
• Task bars

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Components

• An important aspect of components is that they
  should model real-world objects as closely as
  possible, including relationships to other
  objects.
• The components should be easy to combine,
  provision and monitor so that the appropriate
  relationships are maintained between the two
  enterprise sites.

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Components.

• NMS also have other components that add value by
  being as loosely coupled as possible, such as
• Scheduling facilities
• Virtual connection creation, modification, and
  deletion facilities
• NE firmware backup and restore features
• NE configuration database backup and restore,
  including network inventory details like port
  configuration settings, IP addresses, protocol
  settings, and virtual connections.

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Cross-functional Cooperation

• The complexity of NMs software development is
  such that many different people are generally
  involved in its production, including
• Sales and marketing executives
• Specifications and release planning experts
• Designers and domain experts
• Developers
• QA/Test personnel
• IT Managers
• End Users

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Cross-functional

• Quality Assurance (QA) can also assist in the
  early stages of development by first testing
  paper models and later testing stubbed software
  builds. These builds provide the skeleton of the
  end system with much of the function not yet
  implemented.
• The setup and maintenance of modern NEs
  increasingly require professional system
  administration skills. The contribution that IT
  can make to this is significant, particularly
  when many users are sharing the NEs.

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Cross-functional

• Ownership and moving around the development
  environment need to be balanced against the needs
  of the developers. These are include
• GUI
• Backend
• Middleware
• Database
• Deployment facilities for software installation
  and upgrade

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Software Deployment

• Deployment software is the first thing the end
  users
• sees during installation of a give NMS. The
  following are guidelines for successful
  deployment
• Ease of use the NMs Should install/upgrade
  easily.
• Speed deployment should be fast, minimizing
  downtime.
• Function deployment should, if possible, not
  require any downtime as new code is applied.
• Auditable it should be possible to verify that
  new code has been successfully (or
  unsuccessfully) deployed.
• Ease of removal the NMs should uninstall
  cleanly and efficiently.

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Smarter NMs

• NMs (Network Management System) is a term that
  describes a computer based software application
  suite dedicated to the management of networks of
  network elements.

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Smarter NMs.

• NMs must increasingly support high level of
• Reliability
• Availability
• Maintainability
• Preprocessing NE requests in order to reduce the
  number of messages sent to the network
• Discovering static NE data
• Minimizing the amount of data retrieved from NEs.

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Adding Service Management

• The NMs offers a high-level service management
  capability over a MPLS backbone , because NMs
  deals interms of services rather than just
  connections and devices.
• Service management can be made up of more than
  one connection and requires a new type of managed
  object for
• Visual representation
• Provisioning
• Monitoring
• Auto-learning

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MPLS SP Score

• An interesting aspect of MPLS is that
  it will allow enterprise network cores to become
  more generic. Regardless of traffic type, it
  will be transported over LSPs/tunnels.

Cross Connections To SP Core
MPLS SP Score
FR
FR
Ethernet
Ethernet
ATM
ATM
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• NEs must provide
• Unified signaling across multiple domains
• Srevice level traps.
• Implementing services is difficult in a network
  comprised of several different domains, such as
  ATM, IP, MPLS, Frame Relay and X.25.

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NMs Structure

• Most NMs are vertical applications and Stovepipe
  fashion is implemented and data flows up and
  down.
• There is little horizontal communication between
  the stovepipes because they are both database and
  NE-centric and fulfill specific FCAPs (fault,
  configuration, accounting, performance and
  security) function.

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FCAPS STRUCTURE

• FCAPS function are the OSI functional areas of
  network management.The following figure
  illustrates the baseline FCAPs structure.

Database (Schema)
SQL
Database Access Layer
Fault Management
Configuration Management
Performance Management
Security Management
Accounting Management
Database Access Layer
Notifications, Responses
Sets, Gets
Managed Network (Object Model)
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NMs.

• NMs needs additional software such as
• Toplogy management
• NE firmware backup and restore
• NE configuration and database backup and restore.
• Topology components may contain subordinate
  objects, such as
• Nodes contain interfaces
• Interfaces carry virtual connections
• Links join together adjacent interfaces

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Smarter MIBs (Management Information Base)

• MIBs represent a shared name space between SNMP
  agents and Managers.
• They allow an operator to leverage the management
  facilities deployed in the network.
• MIB notes are primarily intended to promote NE
  manageability.

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NE Manageability

• High levels of NE manageability offer a number of
  benefits
• The NE is easier and cheaper to incorporate into
  a network and an NMs.
• The specific NE features are easier to access and
  manage.
• End-user confidence levels are raised with regard
  to the vendor.
• The NE acquires a degree of product
  differentiation.

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MIBs

• Some aspects of MIBs that improve manageability
  are
• MIB Note Avoid MIB object semantic dependencies
• MIB Note Provide default MIB object values
• MIB Note Centralize MIBs to match NE features.

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MIB table column

• Semantic dependencies complicate provisioning
  code because the NMs software has to understand
  the columnar relationships. In addition, they
  also complicate the database schema when the
  columnar relationships have to be duplicated.
• Default values can be given to extraneous MIB
  objects. This object is used when creating a
  tunnel in which the user wants to constrain the
  signaling path through an MPLs cloud so that it
  uses only a specific type of interface on each
  hop.

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MIB table.

• This is similar to solution engineering
  considerations MIBs should be structured so that
  solution components are clearly expressed and
  easily accessed.
• MIB Notes provide good reason for the developers
  of NMs maintaining the MIBs to work in close
  cooperation with the NE developers.

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One Data Model

• The data stored and maintained in the managed
  network must, at some point, be imported into the
  NMS and stored in some type of persistent
  repository.
• Repository data is manipulated by the NMs and for
  actions such as provisioning, is written to the
  network as MIB object instance values.
• The data model is the glue for bringing together
  the managed NE Data and the users view of the
  network.

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• Maintaining parity between NMs and its managed
  network is fundamentally limited by
• Network size and bandwidth
• NE density the number of managed objects
• NE agent resources
• The NMs must try to maintain data parity and, at
  the same time, minimize NE access.

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Distributed Server and Client

• NMs are increasingly large, complex application
  suites. Rather than using a single server with
  multiple distributed client, more than one server
  machine can be used and it helps to distribute
  the processing among a number of host machines.
• NMs can also be operated in redundant mode. This
  constitute of deploying a primary server with one
  or more backup server.

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Deploying Primary Server

• Allows for the Entire NMS to be backed up in a
  number of configurations
• Hot standby the secondary takes over with no
  data loss.
• Warm Standby The secondary takes over with some
  data loss.
• Cold Standby The secondary is started up and
  switched into services.

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Smarter NEs

• The NEs
• Follow the installed policy guidelines
• Watch for the indicated conditions.
• Execute the required actions.
• Policies are a little like SNMP notifications in
  that the NE performs work independently of the
  NMs.
• The need for advanced, real-time services, such
  as voice and video-overIP, on enterprise and SP
  networks is also resulting in a need for greater
  NE intelligence.

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Policy-Based Network Management (PBNM)

• PBNM is one of the most important direction being
  taken in network management. It recognizes that
  trying to manage individual devices and
  connections using a simple get/set/notification
  mode is no longer sufficient because of the
  demands increasingly being placed on networks.

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PBNM

• PBNM introduces a number of new and interesting
  entities into network management. PBNM
  architectural elements are
• Policy Console
• Policy Repository
• Policy server/decision point (PDP)
• Policy Enforcement Point (PEP)

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Network Management Policies

• Network management policies can be simple
  resource allocation such as
• Give traffic from IP address a. b.c.d. the
  highest priority forwarding treatment.
• Assign email traffic the lowest priority
  forwarding treatment.
• Assign VoIP traffic assured forwarding treatment.

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Network Management

• Other network management policies can be in the
  form of NE configuration information such as
• Protocols
• Interfaces
• Network-wide settings.

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Directory-Enabled Networking (DEN)

• DEN is the way in which the managed objects, such
  as nodes, interfaces, links, virtual connections,
  network clouds, routes and resource blocks are
  represented inside the NMs.
• The purpose of DEN is to bind users and services
  to NEs, Network paths, bandwidth and other
  network parameters.

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DEN

• DEN is a specification of an object-oriented
  information model, such as
• Classes, such as generic nodes
• Class attributes, such as location,
  owner/operator
• Class methods, such as delete a specified node
  for notification
• Class relationships, such as a node that owns
  connections that originate on it and terminate on
  other nodes.

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DEN

• The focus on DEN lies in providing a type of
  single system by combining
• A technology-independent information model.
• A directory system for storing policies, the
  object model and the network devices.
• A policy system as discussed earlier
• A traditional SNMP based NMs.

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Information Model

• There are 2 important standard information
  model
• The common Information Model (CIM)
• An Extension to CIM called Directory-enabled
  networking (DEN)
• CIM is an object-oriented model that describes
  how a system and its components may be managed.

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Information model.

• CIM model components are
• System
• Devices
• Application
• Network
• DEN is an extension of CIM. DEN provides a
  mapping of the information to a format that can
  be stored in an LDAP-based directory system.