Network Management Overview

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 logs • Accept and act upon error detection notifications • Trace and identify faults • Carry out sequences of diagnostic tests • Correct faults

FDDI .... .... .... PC PC PC UNIX UNIX UNIX FM Example User DNS ... RMON Device Firewall / Router ... Internet WWW Server Mail Server

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 Functions • Set 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.

Traffic Monitoring - MRTG

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.

FDDI .... .... .... PC PC PC UNIX UNIX UNIX 網路管理基本方式 network 網管系統 NM ... Notification RMON Device RMON Device Polling Firewall / Router ... Internet

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 Management Station Network Element Management Operation R MA MO Response Event Manager Agent Communication Protocols Communication Protocols Network Legend： MA: Manager Applications MO: Managed Objects R: Real Resource

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。

Network Management Overview