Transcript Data Communications and NM Overview

Lecture 1:
Data Communications and
Network 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
Regional Center
Class 1 switch
Regional Center
Class 1 switch
Sectional Center
Class 2 switch
Sectional Center
Class 2 switch
Primary Center
Class 3 switch
Primary Center
Class 3 switch
Toll Center
Class 4 switch
Toll Center
Class 4 switch
End Office
Class 5 switch
End Office
Class 5 switch
To other
Regional centers
Sectional centers
Primary centers
Toll centers
End offices
To other
Primary centers
Toll centers
End offices
To other
Class 4 toll points
End offices
Legend:
Loop
Direct Trunk
Toll-Connecting Trunk
V oice
V oice
Figure 1.1 Telephone Network Model
Toll Trunk
Operations Systems / NOC
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Operations support systems
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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)
Data Communication Network
Message (Frame)
Application
Application
Client
Station
Switch
Server
Station
Switch
Access
Line
Switch
Mobile Client
Station
Trunk
Line
Switch
Mobile Client
Station
Trunk
Line
Outside
World
Router
Internet/internet
LAN
LAN
WAN
LAN
LAN
LAN
WAN
: router
…
Internet
Configuration
Workstation
(Joe)
Mail Server
Workstation
LAN A
Domain
Name
Server
LAN B
Bridge /
Router
Bridge /
Router
Bridge /
Router
LAN C
Gateway
WAN
Gateway
LAN X
Bridge /
Router
Bridge /
Router
Bridge /
Router
LAN Z
LAN Y
Workstation
PC (Sally)
Mail Server
Internet Topology
http://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
Comparison
Telephone 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
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SNMP(v1, v2, v3)
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ICMP
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Address Resolution Protocol/ (Reverse ARP)
TCP
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Internet Control Message Protocol
Ping , traceroute
ARP/RARP
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Simple Network Management Protocol
Socket
Telnet/SSH
HTTP+XML
Common Network Problems
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Loss of connectivity (Link, Node, Interface)
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Duplicate IP address (Procedural)
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Intermittent(間歇的) problems
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Network configuration issues
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Non-problems
• The cause of failure is a mystery. (Turn off , Turn on)
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Performance problems
Challenges of IT Managers
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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)
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Definition
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OAM&P of Network and Services
OAM&P: Operations, Administration,
Maintenance, and Provisioning)
Goal
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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 functions
Network
Management
Network
Provisioning
Network
Operations
Network
Maintenance
Planning
Fault Management / Service Restoration
Fault Management
Design
Configuration Management
Trouble Ticket
Administration
Performance Management / Traffic Management
Network Installation
Security Management
Network Repairs
Accounting Management
Facilities Installation
Reports Management
& Maintenance
Routine Network
Inventory Management
Data Gathering & Analyses
Figure 1.21 Network Management Functional Groupings
Tests
TT
Trouble Ticket
NM Functional Flow Chart
NOC: Network Operation
Center
I&M: Installation &
Maintenance
Network
Users
Configuration Data
Management
Decision
New
Technology
Performance & Traffic Data
Engineering Group
- Network Planning &
Design
TT Restoration
Operations Group
NOC
I & M Group
-Network Installation &
Maintenance
- Network Operations
Fault TT
Installation
網管五大管理功能領域
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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.700
http://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 where everything is in the network .
障礙管理 (Fault Management)
Tells you what your network is doing.
效能管理 (Performance Management)
Tells you how the network is doing.
計量管理 (Accounting Management)
Tells you when your network is used.
安全管理 (Security Management)
Tells you who is using your network.
障礙管理 (Fault Management)
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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
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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
DNS
UNIX
...
User
PC
FDDI
....
RMON
Device
Firewall
/ Router ....
Internet
....
UNIX
PC
...
Mail
Server
WWW
Server
UNIX
PC
FM例子：障礙存錄
組態管理 (Configuration Management)
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Configuration Management (CM)
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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
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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)
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Security Management (SM)
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The process of controlling access to information on
the networked system.
安全管理之功能
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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)
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Performance Management (PM)
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Measuring the performance of network hardware,
software, and media.
幾個量測例子：
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Overall throughput
Percentage utilization
Error rate
Response time
效能管理之功能
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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)
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Accounting Management (AM)
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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
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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.)
Application
Services
Objects
Objects
Vendor A
Management
Protocol
Objects
Vendor B
Objects
Transport
Protocols
(b)Services
Services and
Protocols
& Protocols
Figure 1.23 Network Management Dumbbell Architecture
Network Management Model
Management
Station
MA
Management Operation
Response
Event
Network
Element
MO
Manager
Agent
Communication
Protocols
Communication
Protocols
Network
Legend：
MA: Manager Applications
MO: Managed Objects
R: Real Resource
R
網路管理構成元素
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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
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管理者 (Manager)
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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)
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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
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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
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Internet網管通信協定：
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SNMP (Simple Network Management Protocol)
OSI網管通信協定：
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CMIS/P (Common Management Information Service /
Protocol)
網路管理資訊
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被管物件(Managed Object, MO)
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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)
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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 Management
Service Management
Network Management
Element Management
Network Elements
Functional Areas
Network Types
Configuration
Stages
Performance
IN
VPN
Accounting
Corporate Network
Change
Fault
WAN
Operation
MAN
Accounting
LAN
Installation
Planning
管理範圍 ?
Network Management
System Management
Data
Voice
Applications Management
Service Management
Eneterprise Management
Disciplines
Video
Multimedia
Information Types
網路管理基本方式
network
NM
PC
UNIX
...
網管系統
FDDI
....
Polling
Firewall
/ Router ....
Internet
Notification
RMON
Device
....
UNIX
PC
...
UNIX
PC
網路管理基本方式 (續)
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Polling (輪詢)
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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)
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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)。