chapter 1 data communications and nm overview. outline analogy of telephone network data and...
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Chapter 1Data CommunicationsandNM Overview
Outline
• Analogy of telephone network• Data and telecommunication network• Distributed computing environment• Internet• Protocols and standards• IT management• Network and system management• Current status and future of network management
Telephone Network
• Characteristics:• Reliable - does what is expected of it• Dependable - always there when you need
it (remember 911?)• Good quality (connection) - hearing each
other well• Reasons:
• Good planning, design, and implementation• Good operation and management of
network
Telephone Network Model
Regional CenterClass 1 switch
Sectional CenterClass 2 switch
Primary CenterClass 3 switch
Toll CenterClass 4 switch
End OfficeClass 5 switch
Regional CenterClass 1 switch
Sectional CenterClass 2 switch
Primary CenterClass 3 switch
Toll CenterClass 4 switch
End OfficeClass 5 switch
Voice Voice
To otherRegional centersSectional centersPrimary centersToll centersEnd offices
To otherPrimary centersToll centersEnd offices
To otherClass 4 toll pointsEnd offices
Figure 1.1 Telephone Network Model
Legend:Loop
Direct Trunk
Toll-Connecting Trunk
Toll Trunk
Operations Systems / NOC• 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)
Data and Telecommunication Network
Terminal
Modem
Voice
Terminal
Modem Modem
Voice
Host
Data communication network
Telecommunication network
Figure 1.3 Data and Telecommunication Networks
Loop Loop Loop
IBM SNA Architecture
Mainframe
Communicationscontroller
Communicationscontroller
Clustercontroller
Clustercontroller
Figure 1.5 IBM Systems Network Architecture Model
Workstation Workstation
DCE with LANDCE.. Distributed Computing Environment
Ethernet
Workstation
Workstation
Host
Host
Workstation
(a) Hosts and Workstations on Local LAN
LAN-WAN Network
LAN A LAN B
LAN C
Bridge /Router
Bridge /Router
Bridge /Router
WANcommunication link
Client/Server Model
Client Server
Controltransfer
Controltransfer
Figure 1.7 Simple Client-Server Model
Request
Response
Client/Server Examples
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• Internet e-mail and much of the network mgmt.
messages are based on UDP/IP• ICMP part of TCP/IP suite
InternetConfiguration
Architecture, Protocols and Standards
• Communication architecture• Modeling of communication systems, comprising
• functional components and• operations interfaces between them
• Communication protocols• Operational procedures
• intra- and inter-modules• Communication standards
• Agreement between manufacturers on protocols of communication equipment on
• physical characteristics and • operational procedures
Communication Architecture
OSI Reference Model
OS
I Lay
ers
and
Ser
vice
s
PDU Communication Model
PDU: Protocol Data UnitPCI: Protocol Control InformationUD: User Data
PDU = PCI + UDUDn = PDUn+1
Gateway
DTE : Data Terminating Equipment
T
N
DP
SNA, OSI, and Internet
Application Protocols
NM Case HistoriesNM Case Histories
Common Network Problems
• Loss of connectivity (Link, Node, Interface)
• Duplicate IP address (Procedural)• Intermittent problems• Network configuration issues• Non-problems• 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”
Please refer to Sec. 1.7 for more details
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.700
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.
NM Components
Interoperability
NMSVendor A
NetworkAgent
NetworkAgent
NetworkObjects
NetworkObjects
NMSVendor B
NetworkAgent
NetworkAgent
NetworkObjects
NetworkObjects
Messages
Services & Protocols
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)
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 。
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
Customer ManagementCustomer Management
Service ManagementService Management
Distributed System ManagementDistributed System Management
Network ManagementNetwork Management
Element ManagementElement Management
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) 。
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