Network Management

.Chapter 1

Data Communications

and

NM Overview

2"Network management includes the deployment,

integration and coordination of the hardware,

software, and human elements to monitor,

test, poll, configure, analyze, evaluate, and

control the network and element resources

to meet the real-time, operational

performance, and Quality of Service

requirements at a reasonable cost."

*T.Saydam, T. Magendaz From Networks and Network Management into Service and Service Management Journal of Networks and System Management, Vol.4, No.4, Dec. 1996

What is Network Management?*

More recent Definition

Network Management refers to the activities,

methods, procedures and tools pertaining to

the operation, administration, maintenance

and provisioning of networked systems

Alex Clemm: Network Management

Fundamentals, Cisco Press, 2006

3

NETWORK MANAGEMENT

Properties

Availability

Reliability it almost always provides service of communication that we expect of it.

Performance

Stability

Security

Simplicity in accounting

Quality of service

4

NETWORK MENAGEMENT

NETWORK MENAGEMENT : Goals, Organization, And Function.

NETWORK MENAGEMENT can be defined as a operations , and

Maintenance Provisioning (OAMP) of network and services.

The Operations group is concerned with daily operations in providing

network services.

The network administration is concerned with establishing and

administering overall goals, policies, and procedures of network

management.

The installation and Maintenance group handsels functions that include

both installation and repairs of facilities and equipment.

Provisioning involves network planning and circuit provisioning.

Goal of network Management

Goal of network management.

The goal of network management is to ensure that the users of network

are provided IT services will a quality of service that they expect.

Towards meeting this goal, the management should establish policy to

either formally or informally.

Network management involves strategic and tactical planning of

engineering, operations, and maintenance of network services for

current and future needs at minimum overall cost.

Network management Functions

1) Network and service provisioning.

2) Network and service operations.

3) Network I&M.

NM Functional Groupings

.

Network Management

Network provisioning

Network Operations

Network Maintenance

Planning

Design

Fault Management /Service Restoration

Configuration Management

Performance/Traffic Management

Security Management

Accounting Management

Reports Management

Inventory Management

Data Gathering Analysis

Fault Management

Trouble ticket

administration

Network Installation

Network Repairs

Facilities Installation

and Maintenance

Routine Network

Tests

Network Provisioning

Network provisioning consists of network planning and design and is

the responsibility of engineering groups.

The engineering groups keeps track of new technologies and

introduces them as needed.

What is needed and when is needed are determine from analysis of

traffic.

Network management tools are helpful to the engineering groups in

gathering statistics and studying trends in traffic patterns for planning

purposes.

Automated operations system help in design of circuits and

performance tune-up.

Network Operations and NOC

The function of network operations are administered by the NOC.

Five network operation are fault configuration, performance , security,

and account management.

They are also responsible for gathering statistics and generating reports

for management system support and users.

Fault Management/Service Restoration: Whenever there is a service failure , it is NOCs recusing the failure,

and restoration of service.

This involves detection and isolation of problem causing the failure,

and restoration of service.

In several failure situations, the network will do this automatically.

This network feature is called self-healing.

In other situation NMS can detect failure of the components and

indicate with appropriate alarms.

Trouble Ticket Administration

Trouble ticket administration is the administrative part of fault

management and used to track the problems in network.

All problems , including non problems, are to be tracked untill

resolved.

Periodic analysis of the data, which are maintained in a database, is

done to establish patterns of the problems for follow-up action.

Configuration management

There are three sets of configuration of the network.

Static configuration

Current configuration

Planned configuration

Cont.

Static configuration and is the permanent configuration of

the network.

However, it is likely that the current running configuration,

which is the second, could be different from that of the

permanent configuration.

Static configuration is one that the network would bring up

if it is started from an idle status.

The third configuration is planned configuration of the

future when the configuration data will change as the

network is changed.

Performance management

Data need to gathered by NOC and kept updated in a timely fashion in

order to perform some of the above functions, as well as tune the

network for optimum performance.

Network statistics include data on traffic, network availability , and

network delay.

Traffic data can be capture based on volume of traffic , network

availability and network delay.

Security Management

Security Management can cover a very broad range of security.

It involves physically securing the network, as well as access to

network by users.

Access privilege to application software is not the responsibility of

NOC unless the application is either owned or maintained by NOC

A security database is established and maintained by NOC for access

to the network and network information.

There are other aspects of security management such as firewall and

cryptography.

Accounting management

Accounting management administers cost allocation of the usage of

network.

Metrics are established to mesure the usage of resources and services

provided.

Network consist of components manufactured by multiple vendors.

Some of the data acquisition has to be manual but most data can be

acquired in an automated mode. The SNMP is the most popular

protocol to acquire data automatically using protocol- and performance

analyzing tools.

Network installation and maintenance

The network I&M group takes care of all

activities of installation and maintenance of

equipment and transmission facilities.

Challenges of IT Managers

Rapid advance of technology

Problem analysis

Anticipate customer demands->fulfil

Diagnose problems or outages in non disrupting manner

Maintain reliability, that is , make changes, upgrades, etc.

without disrupting the network.

NETWORK MANAGEMENT MODEL

ORGANIZATION MODEL

INFORMATION MODEL

COMMUNICATION MODEL

FUNCTIONAL MODEL

Network

Mangement

Information

Model

Organization

Model

Functional

Model

Communication

Model

Figure 3.1 OSl Network Management Model

. Organized model describes the component of the network management system, their

functions, and infrastructure.

Organization model

Network management components

object, agent, and manager

Functions of components

Relationships

Information model

Deals with the structure and the organization of

management information.

Structure of management information (SMI)

Syntax and semantics

Describes how the management information is

structured

Management information base (MIB)

Organization of management information

Describes the relationship and storage of


.Communication model Transfer syntax with bi-directional messages

Three component to this

Management application process (that function in

application layer)

Layer management(between layers)

And layer operation (which is within the layer)

Functional model User oriented requirements of NM

Application function

Configuration fault performance security and

accounting

ORGANIZATION MODEL

THE ORGANIZATION MODEL DESCRIBES THE

COMPONENTS OF NATWORK MANAGEMENT AND

THEIR RELATIONSHIPS.

Network object consist of network elements

such as hosts, hubs, bridges, routers etc.

They can be classified into managed or

unmanaged objects or elements

OBJECTS

Managed Objects:- Management process

running in them called an agent.

Unmanaged Objects:-

. Manager

Manages the managed elements

Sends requests to agents, retrieves management information &

stores it in MDB

Monitors alarms .

Agent

Gathers information from objects

Configures parameters of objects

Responds to managers requests

Generates alarms and sends them to managers

Managed object

Network element that is managed, e.g., hubs, bridges, etc..

All objects are either not managed or manageable (more

expensive)

. Agent built into network elementExample: Managed hub, managed router

A manager can manage multiple elements

Example: Switched hub, ATM switch

MDB is a physical database

Unmanaged objects are network elements

that are not managed - both physical (unmanaged

hub) and logical (passive elements)

MANAGERS

The manager manages the managed element(Agent).

There are database in the manager but not in the agent.

The manager queries and received management data from

agent, processes them and store them into the database.

Manager

Managed objects

Unmanaged objects

Figure 3.2 Two-Tier Network Mangement Organization Model

Agent process

MDB

MDB Management Database

Three tier configuration

The intermediate layer acts as both agent and manager.

As manager it collects data from the network elements,

process them, store the results in its database.

As agent, it transmits information to the top level manager.

For example an intermediate system is used for making

statistical measurements on a network and passes the

information as needed to the top level manager.

An intermediate NMS could be a local site of a network

and the information is passed on to the remote site.

Three Tier configuration

Middle layer plays the dual role

Agent to the top-level manager

Manager to the managed objects - e.g., collects data

Example of middle level: Remote monitoring agent (RMON)

Examples:

Statistical measurement on a network

Local site passes information to a remote site

Agent / Manager

Managed objects

Agent process

Manager

Figure 3.3 Three-Tier Network Mangement Organization Model

MDB

MDB


Manager of Managers

Network domains can managed locally; and global view of

the networks can be monitored by a manager of

managers(MoM). MoM

Agent

Agent NMSManager

Managed objects

Managed objects

Figure 3.4 Network Mangement Organization Model with MoM

Agent process

MDB

MDB MDB

MoM Manager of Managers

MDB Management DatabaseAgent

Manager

Agent NMS

Agent

Agent NMSManager

. Agent NMS manages the domain.

MoM presents integrated view of domains

Domain may be geographical (cities),

administrative (departments), vendor-

specific products (Cisco), etc.

Peer NMSs

In such situation two network service

providers needing to exchange management

information between them.

Manager NMS

Agent NMS

Agent NMS

Manager NMS

Figure 3.5 Dual Role of Management Process

Interoperability

NMS

Vendor A

Network

Agent

Network

Agent

Network

Objects

Network

Objects

NMS

Vendor B

Network

Agent

Network

Agent

Network

Objects

Network

Objects

Messages

Services & Protocols

Vendor A

(b) Services and Protocols

Application

Services

Management

Protocol

Transport

Protocols

Objects

Objects

Vendor B

Objects

Objects

Figure 1.23 Network Management Dumbbell Architecture

Information Model

Concern with the structure and storage of the

information.

The representation of objects information that are

relevant to their management forms the

management information model.

Information on network components is passed

between the agent and management process.

The information model specifies the information

base to describe managed objects and relationship

between managed objects .

. The structure defining the syntax of

management information is specified by

structure of management information(SMI).

The information base is called the

management information base(MIB).

The MIB is used by both agent and

management process to store and exchange


The MIB associated with an agent is called

agent MIB and MIB associated with

manager is called manager MIB.

.Manager

Managed objects

MDB MIB

Agent process


MIB Management Information Base

Figure 3.6 Network Configuration with Data and Information Base

. The manager MIB consist of information on all the network components that it manages.

Whereas the MIB associated with an agent

process needs to know only its local

information.

. So, manager has two database.

MDB

MIB

The MDB is the real database and contains

the measured or administratively configured

value of the elements of the network.

MIB is virtual database and contains the

information necessary for processes to

exchange information among themselves.

. The MIB that contains data on managed objects need not be limited to just physical elements.

In network management information extends information

beyond the description of network element or objects.

Managed objects can be

Network elements (hardware, system)

hubs, bridges, routers, transmission facilities

Software (non-physical)

programs, algorithms

Administrative information

contact person, name of group of objects

(IP group)

In fact, any type of info that can be included in the MIB can be

managed.

Management Information Tree

Root

Level 1

Level 2

Level 3

Figure 3.7 Generic Representation of Management Information Tree

Cont.

The managed objects are uniquely defined by tree structure

specified by the OSI model and are used in the internet

model.

Generic representation of tree defined by the MIT.

There is a root node and well defined nods underneath

each node at different levels, designated at level 1, level 2,

level 3, etc.

OSI MIT

The root nod does not have an explicit designation.

The root has three nodes in the layer beneath it iso ,itu,

iso itu

The number in each circle identifies the designation of

object in each layer.

Ths iso is designated as 1, org as 1.3, dod as 1.3.6 , internet

as1.3.6.1.

All the internet managed objects will be that number

followed by more dots and numbers.

The names of the nodes are all in lowercase letters

OSI Management Information Tree

iso-itu

2

itu

0

iso

1

org

3

dod

6

internet

1

Figure 3.8 OSI Management Information Tree

iso International Standards Organization

itu International Telecommunications Union

dod Department of Defense

Designation:

iso 1

org1.3

dod 1.3.6

internet 1.3.6.1 all internet managed objects will start with this

Functional model

Communication Model

Information Model deals with how information content is

defined (SMI) and stored (MIB).

Communication Model deals with how information is

exchanged between systems.

Management data are communicated between agent and

manager processes, as well as between manager processes.

Three aspects need to be addressed in communication of

information between two entities: transport medium of

message exchange(transport protocol), message format of

communication (application protocol), and actual

message(command and responses).

Abstract syntax notation one: ASN.1

It is important for communication among systems

that a formalized set of rules is agreed upon on the

structure and meaning of the language of the

communication , namely syntax and semantics of

the language.

Documents

Network Management