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POSTECH DP&NM Lab

Overview of Network Management

J. Won-Ki Hong

Dept. of Computer Science and Engineering

POSTECH

Email: jwkhong@postech.ac.kr

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POSTECH DP&NM Lab

Table of Contents

• Today’s Networks• Network Management Requirements• Network Management Systems• NMS Software Architecture• Distributed Network Management• Proxy Agent• Standard Management Frameworks

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POSTECH DP&NM Lab

FastEthernet

B-ISDN

ATMSDH

PSTN

Computer Networks Telecom Networks

Today’s Networks & ServicesToday’s Networks & Services

ISDN

TokenRing

GigabitEthernet

MPLS

WANs SS#7

IN/AIN

PSDN

PCS

AccessNetworks

Ethernet

World-Wide WebEmail, DNS, FTPNews, Telnet, IRCRealAudio, RealVideoMBone

Video ConferencingElectronic CommerceInternet PhoneBanking, AccountingDistance Learning

Local, Long-distance, Oversea Phone service080, 070, collect-callthird-party IN servicecellular, C2, PCS, TRS

Video-on-DemandTele-conferencingVideo-conferencingInternet Telephony

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POSTECH DP&NM Lab

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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POSTECH DP&NM Lab

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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AgentAgent Agent

AgentAgent Agent

Agent

Collect, organize & interpretOperational Data

AdministratorWorkstation

Management Platform

Observation & Control

mgmt requests/replies

event reports

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Elements of an NMS

NMA

NME Appl

Comm

OS

NME Appl

Comm

OS

NME Appl

Comm

OS

NME

Comm

OS

Network controlhost (manager)

Server(agent)

Workstation (agent)

Router(agent)

NMA = network management applicationNME = network management entityAppl = applicationComm = communications softwareOS = operating system

Networks

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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 u

ser 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 c

an lead to the need of a hierarchy of managers (e.g., top level manager, middle level managers, etc.)

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POSTECH DP&NM Lab

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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POSTECH DP&NM Lab

Architectural Model of NMS Unified user interface

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

...

ManagementInformation

Base

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POSTECH DP&NM Lab

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 al

l 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 Management clients (PCs, workstations)

Network

Network

Management server

Management application

MIB

Element manager

Element manager

Network resources (servers, routers, hosts) with management agents

Management server

Management application

MIB

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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

Proxy Agent

Protocol stack

Client proxy stub

Protocol stack

Proprietary management interface

Server proxy stub

Management application

Client stub

Protocol stack

Server stub

Protocol stack

Standard operations and event reports

Proprietary operations and event reports

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POSTECH DP&NM Lab

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)

• Web-based Enterprise Management (DMTF)– CIM, XML, Web Services

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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

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Useful Internet Resources• Web Sites

– http://snmp.cs.utwente.nl/ (SNMP, NM RFCs)– http://www.itu.int/ITU-T/studygroups/com04/ngn-mfg/index.html (N

GN Management Focus Group)

– http://www.tmforum.org/ (TM Forum)– http://www.ietf.org/html.charters/wg-dir.html (IETF)– http://www.dmtf.org (DMTF)

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Questions?