Basic Ingredientsof Network Management

Woraphon Lilakiatsakun

Basic components Fig 3-1

Network devices A NE (network element) must offer a

management interface for management purposes Allow managing system to send requests

( configure, retrieve statistical data and etc) Send information (response and unsolicited )

Manager – a managing application who in charge of the management

Agent – a NE who support the manager by responding its requests

Manager-agent communication Fig 3-2

Management agent

Consists of 3 parts A management interface A Management Information Base The core agent logic

Management interface Support a management protocol

that define rule of conversation Communication between the

managed network element For example

To open management session To request to retrieve statistical data To request to change configuration

Management Information Base (MIB) Conceptual data store (management

information) that contain management view of devices

A type of database used to manage the devices in a communications network. It comprises a collection of objects in a (virtual) database used to manage entities (such as routers and switches) in a network. (Ref. from wikipedia)

MIB related standard RFC 1155

Structure and Identification of Management Information for TCP/IP based internets

RFC 1157 Simple Network Management Protocol

RFC 1213 Management Information Base for Network

- Management of TCP/IP based internets

MIB – OID Tree

OID = 1.3.6.1 (internet)

OID = 1.3.6.1.4.1.2682.1 (dpsAlarmControl)

Core agent logic Translates between the operation of the

management interface, MIB, and actual device Ex. Translate the request to “retrieve a

counter” into internal operation that read out a device hardware register.

Additionally, it can include more management functions that offload the processing required by management app. Pre-correlated raw events before sent out

An anatomy of management agent Fig 3-4

Management information (1/2) The version of installed software

To decide which devices need to have new software

Utilization of port Whether capacity upgrades are necessary

Environmental data (temperature and voltage) Ensuring that a device is not overheating

Fans What is causing the temperature to rise

Management information (2/2) Packet counters for different interfaces

Whether the network is under a certain type of attacks (DoS)

Protocol timeout parameter To fine tune network communication

performance Firewall rules

Security purposes others ?

Managed object (MO) Refer to “ a chunk of management

information that exposes one of the real world aspects” Ex. MO could represent a device fan along

with its operational state, a port on a line card along with a set of statistical data

MO could be a MIB object in SNMP a parameter in a CLI (command-line

interface) An element of an XML document in web-

based management interface

Not all aspects in the real world are modeled Color of devices

Real world object that MO represents is referred to as the “real resource”

Since management information in MIB represents real resource When querying the MIB for MO representing a

packet counter 3 times, the value returned will be different

Basic parts of network management - refined Fig 3-6

The Management System Tools to manage the network

monitor the network Service provisioning system Craft terminal

In fact, management system is different from management applications

But often we can use both as the same meaning

Manager/agent reference diagram Fig 3-8

Caching MIB Fig 3-9

The Management network Networks for carrying traffic of

subscriber or end user are referred as “production network”

Networks for carrying management traffic are referred as “management network”

Both can be physically separate networks or they can share the same physical network

Connecting a craft terminal to a managed device Fig 3-10

Connecting to multiple devices through a terminal server Fig 3-11

Dedicated Vs Shared Management and Production networks Fig 3-12

Pros of a dedicated management network Reliability

Congestion or network failure occurs somewhere in the network, it makes the devices hard to reach

Also hard to find out what it happen Interference avoidance

Compete with production traffic May interfere high QoS services (voice ,video

streaming) Ease of network planning

No need to consider on management traffic Security

Hard to attack and more secure

Cons of a dedicated management network

Cost and overhead Addition cost for a management

network No reasonable alternative

Some devices do not provide a physical connection for another usage

DSL router cannot be connected with two physical links

Final word Cost is the huge disadvantage So, the management network is

needed only critical area Backbone of service providers or big

enterprises) Hybrid solution

Generally, it shares over production networks

Only critical segments are used as dedicated networks

Managing the management The management support org. is

responsible for making sure that the network is being run efficiently and effectively

These tasks must be performed Monitoring the network for failures Diagnosing failures and communication outages Planning and carrying out repairs Provisioning new services and adding/removing

users

Keeping an eye on performance of the network

Taking preventive measure Planning network upgrades

Increase capacity Planning network topology and

buildout Ensure that the network will meet future

demand

Organization structure Network planning

Analyzing network usage and traffic patterns and planning network build out

Network operation Keeping the network running and

monitoring the network failures Network administration

Installing new devices / software Customer (user) management

Interacting with the customers

Other thing are needed Establishment of process and

operational policies, documentation of operational procedures Well-defined procedures Well-defined workflow Make management consistent and

efficient Collection of audit trails

Automatically logging activities of operations

Network documentation Must be accurate and up-to-date Important for network planning and

software upgrades Identify some discrepancies

Reliable backup and restore procedures Bring network back to live again in case of

disaster Security emphasis

Networks potentially most vulnerable from the inside

Limit the damage that can cause by one person

Management life cycle

Plan Deploy Operate Decommission

Plan Before the network system starts During the network system is running

Management life cycle Deploy

Installation of the equipment Bootstrap mechanism to allow a device to

obtain and IP address and have layer2 or 3 connectivity

Operate Monitoring/troubleshooting/performance

tuning and etc Decommission

Old equipments (old technology) will be replace

TMN-layer: a management hierarchy reference model

BusinessManagement

ServiceManagement

Network Management

Element Management

Network Element

Management layer

TMN (telecommunication Management network) Network element Element management Network management Service management Business management

Network element

It means “the management agent “

It involves with the management functionality Communication pattern (protocols)

Element management Involve managing the individual

devices and keep them running Functions such as

to view and change a network element’s configuration

To monitor alarm messages emitted from elements

To instruct network elements to run self-test

Network management

Concern with keeping the network running as a whole (end-to-end) Monitoring that involves ensuring that

data flow to reach destination with acceptable throughput and delay

Managing multiple devices in a concerted fashion

Service management

Managing the services that the network provides and ensuring those services are running smoothly

Let’s think as ISP (Internet service provider) ?

Business management

Billing and invoicing Help desk management Business forecasting Etc ?