Lecture 1:Data Communications andNetwork Management Overview

Telephone Network

• Characteristics:• Reliable - does what is expected of it• Dependable - always there when you need it• Good quality (connection) - hearing each other

well • Reasons:

• Good planning, design, and implementation• Good operation and management of network

Telephone Network Model

Operations Systems / NOC

Operations support systems http://en.wikipedia.org/wiki/Operational_Support_Systems

Monitor telephone network parameters• S/N ratio, transmission loss, call blockage, etc.

• Real-time management of network• Trunk (logical entity between switches) maintenance

system measures loss and S/N.Trunks not meeting QoS are removed before customer notices poor quality

• Traffic measurement systems measure call blockage. Additional switch planned to keep the call blockage below acceptable level

• Operations systems are distributed at central offices• Network management done centrally from Network

Operations Center (NOC)

ClientStation

Mobile ClientStation

ApplicationApplication

ServerStation

Router

Mobile ClientStation

AccessLine

TrunkLine

Switch

Switch

Switch

Switch

TrunkLine

OutsideWorld

Message (Frame)

Data Communication Network

Internet/internet

LAN

LAN

LAN

WAN

WAN

LAN

LAN

…: router

InternetConfiguration

Internet Topologyhttp://personalpages.manchester.ac.uk/staff/m.dodge/cybergeography/atlas/topology.html

TCP/IP Based Networks

• TCP/IP is a suite of protocols• Internet is based on TCP/IP• IP is Internet protocol at the network layer level• TCP is connection-oriented transport protocol

and ensures end-to-end connection• UDP is connectionless transport protocol and

provides datagram service• E-mail, WWW, FTP, Telnet: TCP/IP• Network mgmt. (SNMP): UDP/IP• ICMP: part of TCP/IP suite

ComparisonTelephone Network TCP/IP, Internet

Terminal

telephone

Terminal

PDAs, PC, Workstations, …

Application (Content)

Voice

Application (Content)

Data: File, Message

Voice, Image, Video.

Bandwidth Requirement

Static (64 kbps)

Bandwidth Requirement

Dynamic (kbps ~ Mbps)

Transmission

Loop: UTP

Trunk: Optical Fiber

Transmission

Access: UTP, Coaxial Cable, …

Trunk: Coaxial Cable, Optical Fiber

Network Elements (NEs)

CPE, Switch, Mux,

Cross connect

Network Elements (NEs)

Hub, Switch, Bridge, Router

Comparison (cont.)Telephone Network TCP/IP, Internet

Addressing

telephone number

Intelligent Networks

Addressing

MAC, IP, Port, Domain Name, URL

Network Configuration

fixed, or

seldom changed

Network Configuration

Changed frequently

Growth

Stable, not changed

Growth

grow in dog years, new applications

Network Management

Well planned

NOCs

NEs

Network Management

?

Network Management Tools/Systems

Less support in NEs

Protocols used in NM SNMP(v1, v2, v3)

Simple Network Management Protocol ICMP

Internet Control Message Protocol Ping , traceroute

ARP/RARP Address Resolution Protocol/ (Reverse ARP)

TCP Socket

Telnet/SSH HTTP+XML

Common Network Problems

• Loss of connectivity (Link, Node, Interface)

• Duplicate IP address (Procedural)

• Intermittent( 間歇的 ) problems

• Network configuration issues• Non-problems

• The cause of failure is a mystery. (Turn off , Turn on)

• Performance problems

Challenges of IT Managers

• Reliability• Non-real time problems• Rapid technological advance• Managing client/server environment• Scalability• Troubleshooting tools and systems• Trouble prediction• Standardization of operations - NMS helps• Centralized management vs “sneaker-net”

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.

Top-down View of NM functionsNetwork

Management

NetworkProvisioning

Network Operations

NetworkMaintenance

Planning

Design

Fault Management

Trouble Ticket

Administration

Network Installation

Network Repairs

Facilities Installation

& Maintenance

Routine Network

Tests

Fault Management / Service Restoration

Configuration Management

Performance Management / Traffic Management

Security Management

Accounting Management

Reports Management

Inventory Management

Data Gathering & Analyses

Figure 1.21 Network Management Functional Groupings

NM Functional Flow Chart

NOC: Network Operation Center

I&M: Installation & Maintenance

TTTrouble Ticket

網管五大管理功能領域 管理功能領域 (Management Functional

Areas, MFAs) 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)

ITU-T X.700ITU-T X.700http://www.oreilly.com.tw/sample_chap/a030_03.pdf

網管五大管理功能領域 組態管理 (Configuration Management)

Tells you Tells you wherewhere everything is in the network . everything is in the network . 障礙管理 (Fault Management)

Tells you Tells you whatwhat your network is doing. your network is doing. 效能管理 (Performance Management)

Tells you Tells you howhow the network is doing. the network is doing. 計量管理 (Accounting Management)

Tells you Tells you whenwhen your network is used. your network is used. 安全管理 (Security Management)

Tells you Tells you whowho is using your network. is using your network.

障礙管理 (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)

Use of Trouble-Ticket Systems

障礙管理之功能 Maintain and examine error logs Accept and act upon error detection

notifications Trace and identify faults Carry out sequences of diagnostic tests Correct faults

障礙管理實例

InternetInternet

RMONDevice

UNIX....

FDDI

UNIX PC

Firewall/ Router ....

...

....

...

PC UNIX

PC

UserUser DNS

MailServer

WWWServer

FM 例子：障礙存錄

組態管理 (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.

組態管理之功能 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 例子 : Auto Discovery

CM 實例 : 中華電信 (CHTNet)

安全管理 (Security Management)

Security Management (SM) The process of controlling access to information on

the networked system. 安全管理之功能

The creation, deletion, and control of security services and mechanisms.

The distribution of security-relevant information. The reporting of security-relevant events.

效能管理 (Performance Management)

Performance Management (PM) Measuring the performance of network hardware,

software, and media. 幾個量測例子：

Overall throughput Percentage utilization Error rate Response time

效能管理之功能 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.

PM例子|網路訊務量監測

計量管理 (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.

計量管理之功能 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.

Interoperability (cont.)

Services & Protocols

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

網路管理構成元素 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)

網路管理角色 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。

網路管理協定 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 Protocol) OSI 網管通信協定：

CMIS/P (Common Management Information Service / Protocol)

網路管理資訊 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 。

Source: IEEE Communications Magazine • May 1993

Status and Future Trends

• Status: • SNMP management• Limited CMIP management• Operations systems• Polled systems

• Future trends:• Object-oriented approach• Service and policy management • Business management• Web-based management

管理金字塔 (Management Pyramid)

Business ManagementBusiness Management

Service ManagementService Management

Network ManagementNetwork Management

Element ManagementElement Management

Network ElementsNetwork Elements

Network Management

System Management

Applications Management

Service Management

Eneterprise Management

Data

Voice

Video

Multimedia

LANMAN

WANCorporate Network

VPNIN

Configuration

Performance

Accounting

Fault

Accounting

Planning

Installation

Operation

Change

Network TypesNetwork TypesNetwork TypesNetwork Types

Functional AreasFunctional AreasFunctional AreasFunctional Areas

StagesStagesStagesStages

Information TypesInformation TypesInformation TypesInformation TypesDisciplinesDisciplinesDisciplinesDisciplines

管理範圍管理範圍 ??

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) 。