Network Management Overview

Yen-Cheng Chen

Network Management (NM)

Definition OAM&P of Network and Services OAM&P: Operations, Administration,

maintenance, and Provisioning)

Goal To ensure that the users of a network

receive the IT services with the quality of service (QoS) that they expect.

Five Functional Areas

障礙管理 (Fault Management) 組態管理 (Configuration

Management) 安全管理 (Security Management) 效能管理 (Performance

Management) 計量管理 (Accounting

Management)

Fault Management

Fault Management (FM) Detection of a problem, fault

isolation and correction to normal operation.

FM involves the following steps: Discover the problem. Isolate the problem Fix the problem (if possible)

FM Functions

Maintain and examine error logsAccept and act upon error detection notificationsTrace and identify faultsCarry out sequences of diagnostic testsCorrect faults

FM Example

InternetInternet

RMONDevice

UNIX....

FDDI

UNIX PC

Firewall/ Router ....

...

....

...

PC UNIX

PC

UserUser DNS

MailServer

WWWServer

Event Logs

Configuration Management

Configuration Management (CM) The process of finding and setting up

(configuring) network devices.

CM identifies, exercises control over, collects data from, and provides data to networked systems.

CM FunctionsSet the parameters that control the routine operation of the networked system.Associate names with managed objects and sets of managed objects.Initialize and close down managed objects.Collect information on demand about the current condition of the networked system.Obtain announcements of significant changes in the condition of the networked system.Change the configuration of the networked system.

CM Example: Auto Discovery

CM Example: CHTNet

Security Management

Security Management (SM) The process of controlling access to

information on the networked system.

SM Functions The creation, deletion, and control of

security services and mechanisms. The distribution of security-relevant

information. The reporting of security-relevant events.

Performance Management

Performance Management (PM) Measuring the performance of

network hardware, software, and media.

Performance Measurements ： Overall throughput Percentage utilization Error rate Response time

PM Functions

Gather statistical information.Maintain and examine logs of system state histories.Determine system performance under natural and artificial conditions.Alter system modes of operation for the purpose of conducting PM activities.

Tra

ffic

Monit

ori

ng -

M

RTG

Accounting Management

Accounting Management (AM) Tracking each individual and group

user's utilization of network resources to better ensure that users have sufficient resources.

AM enables charges to be established for the use of network resources, and the costs to be identified for the use of those network resources.

AM Functions

Inform users of costs incurred or resources consumed.Enable accounting limits to be set and tariff schedules to be associated with the use of resources.Enable costs to be combined where multiple resources are invoked to achieve a given communication objective.

網路管理基本方式

InternetInternet

RMONDevice

UNIX....

FDDI

UNIX PC

Firewall/ Router

網管系統網管系統網管系統網管系統

.......

PollingPolling NotificationNotification

....

...

PC UNIX

PC

NMNMNMNM

network

RMONRMONDeviceDevice

網路管理基本方式 ( 續 )Polling ( 輪詢 ) 網管系統主動至被管設備要求網管相關資訊 。 一般採用週期性輪詢，週期長短視需要而定，一

般設為 5~15 分鐘。Notification ( 通報 ) 網路設備自行發現問題時，主動向網管系統發出

事件報告 (Event Report) 。

Network Management Model

Legend ：MA: Manager ApplicationsMO: Managed Objects

R: Real Resource

Network Network

AgentAgent

R

Communication Protocols

ManagerManager

MAMAManagement Management OperationOperation

ResponResponseseEvenEven

tt

Communication Protocols

MOMO

ManagementStation

NetworkElement

NM Components

管理者 (Manager)代理者 (Agent)網路管理通信協定 (Network Management Protocol)網路管理資訊 (Network Management Information)

Manager vs. Agent

管理者 (Manager) 執行各項用來監督 (Monitor) 及控制

(Control) 網路設備的網管應用程式代理者 (Agent) 位於網路設備端，負責接受從管理者端送來

之要求，執行所付予之工作，並將結果回報給管理者。

Network Management Protocols

網路管理協定專為管理者與代理者所設計之通信協定。網路管理協定提供管理者與代理者間交換網管資訊標準方式。目前主要兩種網管通信協定 Internet 網管通信協定：

SNMP (Simple Network Management) OSI 網管通信協定：

CMIS/P (Common Management Information Service / Protocol)

Management Information Model

被管物件 (Managed Object, MO) 將待管之網路資源，抽象化為物件，稱被管

物件，簡寫 MO 。 被管物件所代表之網路資源可大可小，大可

至代表整個網路設備如 ATM 交換器，小可至代表某一網路元件之參數，如介面卡之狀態。

管理資訊庫 (Management Information Base) 被管物件之集合，簡寫 MIB 。