Overview of Network Management

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Overview of Network Management

• J. Won-Ki Hong
• Dept. of Computer Science and Engineering
• POSTECH
• Tel [phone]
• Email jwkhong_at_postech.ac.kr

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Table of Contents

• Todays Networks
• Network Management Requirements
• Network Management Systems
• NMS Software Architecture
• Distributed Network Management
• Proxy Agent
• Standard Management Frameworks

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Todays Networks
SDH
FDDI
Access Networks
ATM
Token Ring
PCS
SS7
PSDN
WANs
Fast Ethernet
PSTN
Gigabit Ethernet
ISDN
B-ISDN
IN/AIN
Ethernet
Computer Networks
Telecom Networks
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NM Users Requirements

• Controlling corporate strategic assets
• effective control of network computing
  resources
• Controlling complexity
• continued growth of devices, users, applications
  protocols
• Improving service
• users expect better service with increased
  resources
• Balancing various needs
• must assign and control resources to balance
  various needs
• Reducing downtime
• more users and applications depend on
  availability
• Controlling costs
• effective resource utilization in order to
  control costs

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NM Functional Requirements

• Fault Management
• detection, isolation and correction of abnormal
  operations
• Configuration Management
• identify managed resources and their
  connectivity, discovery
• Accounting Management
• keep track of usage for charging
• Performance Management
• monitor and evaluate the behavior of managed
  resources
• Security Management
• allow only authorized access and control

FCAPS
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Fault Management

• concerned with
• providing a reliable networking environment
• ensuring that the systems as a whole, and each
  essential component individually, are in proper
  working order
• redundant components and routes can be used to
  increase fault tolerance
• when a fault occurs, the manager should be able
  to
• determine exactly where the fault (i.e., abnormal
  condition) is
• isolate the rest of the network from failure
• reconfigure or modify the network for continued
  operation
• repair or replace the failed components to
  restore the network

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Configuration Management

• concerned with
• initializing a network shutting down part or
  all of the network
• maintaining, adding and updating the
  relationships among components
• monitoring the status of components during
  network operation
• the network manager should be able to
• startup and shutdown operations on a network
• identify the components that comprise the network
  (discovery)
• change the connectivity of the components
  (possibly as a result of network upgrade, fault
  recovery or security checks)
• detect changes in the network configuration

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Accounting Management

• concerned with
• keeping track of the usage of network resources
• charging the use of network resources
• monitoring the end-user activities for possible
  abuse, for suggesting better usage to users and
  for network planning
• the manager should be able to
• specify the kinds of accounting information to be
  recorded at various nodes
• specify the algorithms to be used in calculating
  the charging
• generate accounting reports

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Performance Management

• concerned with
• providing an efficient communication environment
• monitoring and analyzing the performance of the
  components
• making proper adjustments to improve network
  performance
• the manager should be able to
• determine the capacity utilization, throughput,
  the average and worst-case response times
• monitor and gather data on the activities of
  components
• analyze the gathered data and assess performance
  levels
• determine the sources of performance problems
  fix them
• use the performance stats for future network
  planning

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Security Management

• concerned with
• providing a secure networking environment
• preventing hacking, illegal and unauthorized
  access
• managing information protection and
  access-control facilities
• the manager should be able to
• generate, distribute and store encryption keys
• maintain and distribute passwords and other
  authorization or access-control information
• monitor and control access to networks
• collect, store and examine audit records and
  security logs
• enable disable the logging facilities

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Network Management Systems

• A network management system (NMS) is a collection
  of tools for network monitoring and control
• based on the manager-agent paradigm
• the manager sends mgmt requests to one or more
  agents
• an agent performs the requested operation and
  returns results
• when agents detect faults and they report to the
  manager
• NMS typically provides a GUI through which most
  or all management tasks can be performed
• Many commercial and freely available NMSs exist
• HP OpenView, IBM NetView, Sun Net Manager, etc.
• research prototypes from CMU, MIT, UC Davis, U.
  of Twente

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Elements of an NMS
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Network Management Entity (NME)

• NME is a collection of software devoted to the
  network management tasks
• is typically known as an management agent
• Each NME performs the following tasks
• collects statistics on communications and
  network-related activities
• stores statistics locally
• responds to commands from the network manager,
  including commands to
• transmit collected stats to network manager
• change an attribute value
• provide status information
• generate artificial traffic to perform a test
• etc.

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Network Mgmt Application (NMA)

• NMA is a collection of software for performing
  network monitoring and control
• is typically known as network manager
• NMA provides an operator interface to allow an
  authorized user to manage the network
• NMA responds to user commands by displaying
  information and/or issuing commands to NMEs
• Standard protocols (e.g., SNMP, CMIP) are used to
  manage a multi-vendor network
• there may be more than one NMA in a large network
  which can lead to the need of a hierarchy of
  managers (e.g., top level manager, middle level
  managers, etc.)

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NM Software Architecture

• User Presentation Software
• interfaces between user and NM software
• a unified user interface desirable
• includes graphical tools to display summarized NM
  information
• Network Management Software
• a set of NM applications (configuration,
  performance, etc.)
• a set of application elements (alarm handling,
  logging, etc.)
• NM data transport service
• Communication and Database Support Software
• local Management Information Base (MIB) access
  module
• communications protocol stack (e.g., TCP/IP, OSI)
  to interact with remote agents and managers

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Architectural Model of NMS
Presentation of network management information to
users
Network management application
...
Network management application
...
application element
application element
application element
Network management data transport service
MIB access module
Communication protocol stack
Managed networks
Management Information Base
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Distributed Network Management

• Resources to be managed are widely distributed
• widespread use of departmental LANs
• need for local control optimization of
  distributed applications
• Hierarchical NM architecture desirable
• distributed NMSs are given limited access for
  network monitoring and control of departmental
  resources
• top-level NMS has a global access rights and the
  ability to manage all network resources
• Benefits of Distributed NM
• NM traffic overhead is minimized - traffic is
  localized
• Dist. mgmt offers greater scalability
• use of multiple NMSs eliminates the single point
  of failure

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Typical Dist. Mgmt System Architecture
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Proxy Agents

• Managed resources may have various mgmt
  interfaces
• some with different mgmt protocols (e.g., OSI vs.
  SNMP, XML vs. SNMP)
• some with proprietary mgmt interfaces (e.g.,
  older systems)
• small systems not capable of possessing NME
  (e.g., modems)
• Proxy agents are used to manage these devices
• managers use standard protocols to communicate
  with proxies
• proxy agents use proprietary protocols to
  communicate with proprietary devices
• proxy agents perform translations between
  managers and proprietary devices
• an agent to the manager and a manager to
  proprietary devices

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Proxy Agent Architecture
Proprietary management interface
Proxy Agent
Management application
Client proxy stub
Server proxy stub
Client stub
Server stub
Protocol stack
Protocol stack
Protocol stack
Protocol stack
Proprietary operations and event reports
Standard operations and event reports
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Standard Management Frameworks

• Internet Network Management Framework (IETF)
• SNMPv1 (Internet Full Standard)
• SNMPv2 (Internet Full Standard)
• SNMPv3 (Internet Proposed Standard)
• OSI Network Management Framework (ISO/ITU-T)
• CMIP (X.700 Series)
• Telecommunication Management Network (ITU-T)
• TMN (M.3000 Series)
• Distributed Management Task Force (DMTF)
• DMI, CIM, WBEM

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Summary

• Network Management Requirements
• Users Requirements
• Functional Requirements (FCAPS)
• Network Management Systems
• Network Management Entity (NME)
• Network Management Application (NMA)
• NMS Software Architecture
• Distributed Network Management
• Proxy Agent
• Standard Management Frameworks
• READ Chapter 1 of Stallings

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Useful Internet Resources

• USENET News Groups
• comp.protocols.snmp
• info.snmp
• comp.dcom.net-management
• Web Sites
• http//netman.cit.buffalo.edu/
• http//snmp.cs.utwente.nl/
• http//www.tmforum.org/
• http//www.ietf.org/html.charters/wg-dir.html
• http//www.dmtf.org

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Questions?