Network Management: Goals, Organization and Functions

Network Management

Network Management: Goals, Organization and Functions

2

Telecomm/Data Network

A telecommunication/Data network is composed from many network elements (switching systems, terminals, circuits etc.) which provides certain services for the users. The collection of such elements forms the system resources.

Heterogeneous (Platforms/Protocols)

Complex (Many layered)

Service Management (Fast service setup)

WIMAX

Access Metro Core

3000R

OA

DM

6500

View of a Telecomm/Data Network

6100

(MSAP)

GPON

IPDSLAM

GbE

Access Networks

Optical Transport Pa

ck

ets

Management

Access Networks

Optical Transport Pa

ck

ets

OSP OLT

R-ONT

R-ONT

R-ONT

R-ONT

R-ONT

VoIP

ISP Peering

Internet

Video

Services

100FX

ADSL2+

VDSL2

GbE

ADSL2+

VDSL2

PSTN

2x 10 GE

/ OC48

Network Management Systems

A network management systems are used to control the system and its resources by controlling its usage, access monitoring and reporting its current and historical status.

Judgment, forecasting, decision making, analyzing data, and make positive efforts to maintain quality of service.

Overview: Network Management

AgentAgent Agent

Agent

Collect, organize & interpret

Operational DataAdministrator

Workstation

Management Platform

Observation

& Control

mgmt requests/replies

event reports

Agent Agent

Agent

OAM&P(operations, administration, maintenance, and provisioning)

Provisioning

- Planning

- Design

Network Management

Defined As OAMP (Operations, administration, maintenance and provisioning) of

Network and Services

Goal Main goal of Network Management is to ensure that the users of the

network receives the information technology services with the QoS that they expect.

SLA – Formally or Informally – Operation Critical Services should be un-interrupted 24x7 and other non – critical 8x5

From business administration point of view network management involves strategic and tactical planning of engineering, operation and maintenance of network services for current and future needs.

Network Management Function Network Provisioning, operations, I&M

Systems and Network Management SNMP 6

Network Management Operation

Network Provisioning Network planning & Design; Responsibility of engineering group

Keep track of new technologies and apply based on analysis of network traffic and performance data collected through network operations.

Use Network Management Tools

Network Operations NOC is responsible for discharging ISO defined five OSI network

management applications – fault, configuration, performance, security & Accounting

Fault Management

Accounting Management

Configuration Management

Performance Management

Security Management


Fault Management Fault : A fault is an abnormal condition that requires management attention

for repair whereas error is a single event. A fault is usually indicated by failure to operate correctly or by excessive errors. For example if a communication line is physically cut no signal will get thru so that there is persistently high bit error rate.

Fault Management Is the process of locating faults

Related to service failure

Main Steps Discover the problem

Isolate the problem

Fix the problem (if possible)

How do we do it Trouble Ticket (I&M group)


Accounting Management Accounting Management

NOC administers costs and allocates the use of the network

Measure the usage of network resources and services

Involves tracking individual’s utilization and grouping of network resources to ensure users have sufficient resources

Involves granting or removing permission for access to the network

The reason to do accounting

An end user or group of users may be abusing their access privilege and burdening the network at the expense of others

An end user may be making inefficient use of the network

Network Managers can plan better growth of the network if user behaviour is know.


Configuration Management Config Mgmt is related to initializing the network and gracefully shutting it

down. Manage the behaviour of devices thru software. Same device could be used as router or end device with the help of software with set of attributes and values.


Configuration of network devices controls the behavior of the network.

Process of finding and setting up these critical devices

Three types of configurations – Static or permanent, Dynamic or current & Planned

NOC has displays which shows dynamic configurations of the network and its status

Shows Failure points, traffic patterns and performance


Performance Management Performance Concerns

What is the level of network utilization

Is there excessive traffic

Has thruput has been reduced to unacceptable limits

Are there any bottlenecks

Is response time increasing

Taken care thru monitoring & control

Performance Management Involves measuring the performance of the network hardware, software and media

NOC gathers data and keep it upto date to perform above stated objective as well as tune the network for optimum performance.

Examples of measured indicators are – network traffic/overall throughput, network availability/percentage utilization, Error rates, Response time/delays.

Traffic analysis is useful in detecting trends and future planning, performance data on availability and delay is useful for tuning the network and increase the reliability and improve the response time.


Security Management

Security Management Is the process of controlling access to the information on the network

Provides a way to monitor access points and records information on a periodic basis

Provides audit trails and sounds alarms for security breaches

A security database is established and maintained by the NOC for access to network and network information.

Generating, distributing & storing encryption keys

Password and Access control and Authentication

Audit logs Security records

Enabling disabling logging services.


Overview: Network Management

AgentAgent Agent

Agent

Collect, organize & interpret

Operational DataAdministrator

Workstation

Management Platform

Observation

& Control

mgmt requests/replies

event reports

Agent Agent

Agent

OAM&P(operations, administration, maintenance, and provisioning)

Provisioning

- Planning

- Design

Network Management Standards

OSI (CMIP/CMISE) International standard (ISO/OSI)

Data communication networks (LAN/MAN)

Deals with all seven layers

Most complete

Object oriented

Well structured and layered

Complex and consume large resources

Internet Model Industry standard (IETF)

Originally intended for internet components (routers/switches), currently adopted for WANs and Telecomm

Easy to implement/Most widely deployed


Network Management Standards

TMN International standard (ITU-T)

For Telecomm/based on OSI NM model

Addressed both network management and administrative aspects

IEEE LAN/MAN IEEE standard adopted internationally

Addressed management of LANs/MANs

First two layers of OSI model/based on OSI model

Web-based management Web-based Enterprise Management

Java Management Extensions (JMX)


Network Management Models

OSI network model proposes following four management models

Organizational Model Defines Components of network management system, their function & infrastructure

Defines terms object, manager, agent

ISO I0040

Informational Model Structure & Organization of Management Information

ISO I0165 defines SMI & MIB (Structure of management information & management information database)

SMI – how management information is structured

MIB – relationship and storage of information

Communication Model Mode of communication between the entities of organization models

Functional Model Configuration, Fault, Performance, Accounting & Security



Organizational Model

Consists of Managers, Agents and Managed Objects

MDB

Two-tier & Three-tier systems

MoM

Three-tier EMS systems

NMS systems



Information Model

Structure & Storage of Information, e.g. ISBN – “ISBN”, “Chapter”,”Figure”

Specifies the information base to describe managed objects & their relationship

SMI – Syntax & Semantics of management information

MIB – storage of SMI data (used by both manager & agent)

MIB v/s MDB, i.e. meta-data v/s real data

Example data of MIB

Network elements : hubs, bridges, routers, transmission facilities

Software Processes : programs, algorithms, protocols, databases

Administrative information : contact person, account numbers


Management Information Trees

MIT Managed objects are uniquely defined by a tree structure specified by OSI model

Root Node and well defined nodes underneath each node at different levels

Each managed object = a node in the tree

Containment model


ISO-ITU (2)ISO (1)

org (3)

dod(6)

internet(1)

ITU (0)

Managed Object Perspective

Internet Perspective

Access:

Access privilege


Object Type:Object ID & Descriptor (Unique ID & Name of object type)

Syntax:Model of object

Definition:Textual description of object

Status:Implementation Requirements

Managed Object Perspective

ISO Perspective


Object Class:Circular Object

Attributes:Circle, dimensions

Behaviour

Attributes:ellipse, dimensions

Operations:Push

Object Class:Elliptical Object

Notification:Notify changes in attribute values

Managed Object (ISO/IETF)

Characterstics Example

Object Class Packet Counter

Attributes Single-valued

Operation Get,set

Behaviour Retrieve or reset values

Notification Generate notification on change


Characterstics Example

Object type PktCounter

Syntax Counter

Access Read-only

Status Mandatory

Description Counts no. of pkts


Communication Model

The way information is exchanged between the systems

Three important aspects are defined here

Transport medium of message exchange (transport protocol)

Message format of communication (application protocol)

The actual messages (commands & responses)

Connectionless or Connection-oriented (TP4 over X.25 or IP)


Manager Application

Manager Communication Module

Transport Layer

Agent Communication Module

Agent Application

Transport LayerUDP/IP (IETF)OSI Layer (OSI)

SNMP (IETF)CMIP (OSI)

Oper/req/res/traps/notifications


Functional Model Fault Management


Performance Management

Administration Management

Security Management


Network Management Cost Models

Response Time Evaluations

Asynchronous polling

Synchronous polling

tdel,i = average network latency delay between the manager and ith agent

tp = average processing time for handling a single request/response message

tcomp = computation time to process the collected data

Find out the overall response time for both the modes


Network Management Cost Models

Bandwidth Overhead Evaluations

Sreq = Size of a request packet

Sres = Size of a response packet

Ot = transport protocol overhead

P = no. of polling intervals

Find out the network bandwidth overhead


Network Management: Goals, Organization and Functions

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