A Real NMS

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A Real NMS

• Chapter 5
• CIS 536 Network Management
• By
• Kode Venkateswara Rao

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Hewlett Packards OpenView

• The following are the headings under which we
  study the NMS
• FCAPS support Basic NMS application areas.
• MIB support features.
• MPLS Support.
• Policy Support.
• Reliability features, such as support for
  failure.
• Integration with other software.
• Programmability.

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OpenView Network Node Manager

• Central to the function of NNM is the management
  station. This is the computer that performs the
  bulk of data collection like
• a) Collection of information from NEs
  via SNMP.
• b) Processing and archiving data in a
  database.
• c) Distribution to registered
  applications.

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• There can be more than one management station
  which can exchange information with one another.
• Management station can delegate NE data
  collection to collection stations.
• HP suggests that a single management station can
  handle 5000 managed objects.
• Up to 60,000 objects can be managed if collection
  stations are deployed.

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NNM Features

• Discovery and Mapping
• Monitoring
• Notification processing
• Reporting
• Data Warehousing
• Backup and Restore of firmware and configuration
  data
• Java interface for remote access to management
  features
• Remote administration of NMS

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Network Discovery and Mapping

• This NMS feature enables discovery of new NEs.
• Automatic discovery frees the user from
  potentially error prone task of manually entering
  and maintaining the details of deployed NEs.
• Large service providers deploy NMS from the point
  in time that they start to build their networks.

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• Discovery has three main stages. They are
• Initial discovery of previously unknown NEs.
• Examples of Initial Discovery are
• IP address of SNMP agent on the device.
• Inventory details like cards deployed in the
  device.
• Protocols, technologies running on the device
  such as ATM, MPLS, X.25 and so on.
• Virtual connections, traffic profiles, route
  objects and so on.

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• Incremental discovery of changes that occurred to
  previously discovered data.
• Discovery of removal when a Network Element is
  taken out of network, it is automatically removed
  from NMS.

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NNM Discovery and Mapping

• NNM provides and automatic discovery mechanism.
• Discovery process uses SNMP based polling and
  ICMP requests to build a picture of the network.
• Discovery process populates an IP topology
  database using a series of tables like
  Network-level connectivity, Segments, Nodes,
  Interfaces.
• This grouping allows NNM to create logical maps
  of the NEs and to graphically indicate
  operational status using a color, such as green
  for up, red for down, etc.
• An icon representing a network can be expanded to
  show the constituent nodes. In other words,
  containment relationships are depicted clearly.

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Monitoring

• This is a process of recording changes in the
  status of managed objects such as
• Nodes
• Interfaces
• Links
• Virtual Connections
• Ethernet VLANs

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• Status changes can have important bearing on the
  service received by the end user.
• When an interface that is part of an ATM goes
  down, the interface is no longer able to handle
  the traffic. Such a status change may be service
  affecting if there is no backup connection.
• Because of this Monitoring functions are an
  important part of an NMS.
• The same process that carries out discovery also
  executes NNM monitoring. Status changes are
  reflected back into the topology.

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Notification Processing

• An important part of fault management this is
  the (F) part of the FCAPS.
• Following would be the issues for SNMP
  notifications.
• Notifications are not acknowledged by the NMS.
• Notifications are transported using UDP Protocol
  and are unreliable.
• Faulty NEs can generate many notifications.
• Aggregated services which are faulty can produce
  notification storms.

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• When an NMS receives an SNMP trap over an
  unreliable transport, it never acknowledges.
• This helps in scalability and keeps the
  management protocol as lightweight as possible.
• It reduces network congestion.
• When an agent detects a problem, it sends a best
  effort notification message and delegates problem
  resolution to the NMS.
• Networks are designed to have at least 25
  bandwidth free to allow routing, signaling, and
  management protocols to operate at all times.
• If this is followed then agent notifications
  should always get through to the NMS.

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NNM Notification Processing

• NNM uses the term EVENT to describe NE
  notifications as well as messages from other
  sources ( external applications).
• NNM provides an alarm browser for all such
  events.
• Important events can then be configured to show
  up as alarms for operator intervention.

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• NNM distinguishes between notifications and
  events. Lifecycle for a notification is
• An NE sends a notification.
• Notifications is received by NNM and logged.
• NNM distributes the notification to applications
  that are registered for it.
• NNM allows notifications to be paired so that
  notification A indicates a problem and
  notification B indicates problem rectification.
  Such paired notifications assist a network
  operator because they reflect those situations
  when the network self heals.
• When the correction notification does not occur
  then the fault remains active.
• NNM also supports event correlation in which a
  given notification is processed before it is
  forwarded to one of the applications.

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Reporting

• Reporting is one of the most features of an NMS
  in which data is retrieved from the network and
  presented in a specified format.
• This can include the following
• Deployed NEs
• NE configuration
• Interfaces
• Links
• Virtual Connections

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NNM Reporting

• NNM reporting is GUI Based and is accessible
  through a browser. The main options are
• Report Configuration Create, delete and modify
  reports.
• Report Presentation View reports.
• NNM reports can be
• Scheduled
• Configured/viewed using a standard browser
• Automatically emailed to a recipient

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• Examples of NNM pre-configured reports are as
  following
• Accounting
• Availability
• Congestion
• Historical Details
• Inventory
• Performance
• Real-time details
• Thresholds
• Trend Analysis
• Utilization

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Data Warehousing

• NMS provides a persistent repository, that is, a
  commercial database product such as Oracle.
• It is this database that is kept synchronized by
  the NMS Application regarding the network state.
• It also facilitates data security by hosting the
  database in a secure location with access grants
  only to authorized clients.
• The user can view all the necessary information
  to manage the network, such as, Viewing the
  configuration of a given node, Provisioning an
  ATM virtual connection between two nodes and so
  on.
• The database is therefore a key component of the
  NMS. All the FCAPS applications use it.

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Backup and Restore

• In network management both firmware and NE
  configuration are high value items.
• The firmware version on a given NE is subject to
  change as new features and technologies are
  added. It is important to backup the existing
  version before any upgrade.
• Once the NEs have been configured and are
  operational, it is important to be able to backup
  the settings, also called as configuration
  database.
• NNM provides a backup facility that allows a
  snapshot to be taken of the topology and maps.
  These are frozen during the time it takes to copy
  the data into a backup directory. At no time
  during this process do the alarm handling and
  data collection procedures stop.

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Java interface for Remote Access

• Standard Java enabled Web browsers reduce
  investment required for producing client side NMS
  solutions because no development is required for
  client application framework.
• Browser provides execution environment for client
  applications.
• Use of java as number of merits
• Java is object oriented.
• Provides built-in security
• Java is multiplatform programming language
• Java supports field-replaceable packages

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NNM Java Interface

• Java based Web interface in NNM allows user to
  connect to the NNM management station.
• It permits remote viewing of
• Topology
• Alarms
• Node status
• MIBs
• Maps
• Graphs
• Java interface exports management station
  function onto desktop systems equipped with
  standard browsers on Remote clients.

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MIB Support Features

• MIBs provide details concerning the network
  managed objects and form the basis for the NMS
  data model.
• NMS should provide number of baseline features
  for MIB support like
• Load new MIBs
• Support Multiple versions of the same MIB
• Unload MIBs no longer in use
• Browse and analyze MIBs

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MPLS Support

• MPLS nodes have a number of managed objects, the
  status of which can change over time
• Interfaces can be up or down
• Routing protocols such as OSPF, IS-IS can be
  operational or disabled.
• Forwarding table entries can be active or
  inactive
• LSPs can be up or down
• Other MPLS objects that do not change are
• EROs
• Resource Blocks
• Cross-connects

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• NNM provides no special support for MPLS but can
  be extended to use the appropriate MIBs.

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Policy Support

• Network management terms and policies can be used
  to automatically solve recurring problems.
• One example is traffic thresholds. User can set a
  threshold on an interface for the number of
  packets received. If the threshold is exceeded, a
  notification is generated and the NMS can divert
  the traffic.

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NNM Policy Support

• Apart from basic policies like issuing emails in
  response to certain events, NNM requires third
  party products to implement policy handling.
• Policy based applications provide features such
  as
• Application prioritization
• Enterprise policy distribution, example access
  to NEs.
• User-based security policies and so on.

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Reliability Features

• Backup facilities can help in improving
  reliability.
• In case of NMS, this can take the form of
  protecting the central database with a failover
  capability.
• User can deploy a backup version of the database
  that runs in a parallel mode with the primary
  system.
• NNM collection stations can be configured to
  failover to remote management stations.

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Integration with other software

• NMS can be integrated with some ancillary systems
  or applications which can perform the following
• Data export of network topology/inventory data
  for business asset analysis
• Data export of software based modeling packages
  for traffic analysis, network design. Specialized
  software applications can be used to carry out
  offline traffic analysis. A snapshot of the
  discovered topology can be exported into a
  modeling package, and the user can execute
  what-if scenarios. The effects of such changes
  can be viewed offline before making the changes.

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• Integration of alarms with trouble ticket system.
  Alarms generated by the network can be routed via
  the NMS to trouble ticket applications. This
  allows for recording and directing any remedial
  work required to clear the fault.
• Performance analysis regarding the number of
  packets, cells, frames transported by a NE. Many
  NEs generate performance data records (PDR) that
  provide utilization details for
• a) Ports, links and virtual circuit
  utilization
• b) Protocols
• c) Networking technologies

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• Billing Reports generation using CDRs and other
  data such as connection type, class of service.
• Security distribution of keys, user accounts
  and passwords, digital certificates and so on.
• NNM Integration
• Many third party applications like Microsoft
  System Management Server can be integrated with
  NNM.

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Programmability

• Facility of adding software to an NMS can greatly
  extend its usefulness.
• Network management requirements are unique to
  every network, so programmability is an important
  addition.
• NNM Programmability
• NNM allows for user-software to be added to
  enhance the base functions.
• This can include reporting, alarm and event
  processing.

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Summary

• Effective network management requires broad range
  of software tools.
• In NNM Network Management is achieved by using a
  number of software packages.
• Special Software can be employed for billing,
  mediation and performance analysis.
• Minimizing the gap between the network situation
  and that perceived by the NMS is crucial and
  provides a baseline for defining the quality of a
  given NMS.