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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) 。