Lecture 1: Data Communications and Network Management Overview

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Lecture 1Data Communications andNetwork
Management Overview
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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

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Telephone Network Model
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Operations Systems / NOC

• Operations support systems
• http//en.wikipedia.org/wiki/Operational_Support_S
  ystems
• 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)

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Data Communication Network
Message (Frame)
Application
Application
Client Station
Switch
Server Station
Switch
Trunk Line
Access Line
Switch
Trunk Line
Outside World
Mobile Client Station
Switch
Router
Mobile Client Station
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Internet/internet
LAN
LAN
WAN
LAN
LAN
LAN
WAN

router
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InternetConfiguration
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Internet Topology
http//personalpages.manchester.ac.uk/staff/m.dodg
e/cybergeography/atlas/topology.html
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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

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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
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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
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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
• HTTPXML

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Common Network Problems

• Loss of connectivity (Link, Node, Interface)
• Duplicate IP address (Procedural)
• Intermittent(???) problems
• Network configuration issues
• Non-problems
• The cause of failure is a mystery. (Turn off ,
  Turn on)
• Performance problems

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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

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Network Management (NM)

• Definition
• OAMP of Network and Services
• OAMP 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.

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Top-down View of NM functions
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NM Functional Flow Chart
TT Trouble Ticket
NOC Network Operation Center IM
Installation Maintenance
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??????????

• ?????? (Management Functional Areas, MFAs)
• ???? (Fault Management)
• ???? (Configuration Management)
• ???? (Security Management)
• ???? (Performance Management)
• ???? (Accounting Management)

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

• ???? (Configuration Management)
• Tells you where everything is in the network .
• ???? (Fault Management)
• Tells you what your network is doing.
• ???? (Performance Management)
• Tells you how the network is doing.
• ???? (Accounting Management)
• Tells you when your network is used.
• ???? (Security Management)
• Tells you who is using your network.

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???? (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

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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

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??????
User
DNS
...
RMON Device
Firewall / Router
...
Internet
WWW Server
Mail Server
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FM??????
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???? (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.

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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.

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CM ?? Auto Discovery
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CM ?? ????(CHTNet)
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???? (Security Management)

• Security Management (SM)
• The process of controlling access to information
  on the networked system.
• ???????
• The creation, deletion, and control of security
  services and mechanisms.
• The distribution of security-relevant
  information.
• The reporting of security-relevant events.

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???? (Performance Management)

• Performance Management (PM)
• Measuring the performance of network hardware,
  software, and media.
• ??????
• Overall throughput
• Percentage utilization
• Error rate
• Response time

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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.

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PM?????????
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???? (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.

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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.

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Interoperability (cont.)
Services Protocols
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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
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????????

• ??? (Manager)
• ??? (Agent)
• ???????? (Network Management Protocol)
• ?????? (Network Management Information)

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??????

• ??? (Manager)
• ????????(Monitor)???(Control)???????????
• ??? (Agent)
• ???????,??????????????,????????,???????????

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??????

• ????????????????????????
• ???????????????????????????
• ????????????
• Internet??????
• SNMP (Simple Network Management Protocol)
• OSI??????
• CMIS/P (Common Management Information Service /
  Protocol)

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??????

• ????(Managed Object, MO)
• ????????,??????,?????,??MO?
• ????????????????,????????????ATM???,??????????????
  ,????????
• ????? (Management Information Base)
• ???????,??MIB?

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Source IEEE Communications Magazine May 1993
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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

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????? (Management Pyramid)
Business Management
Service Management
Network Management
Element Management
Network Elements
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Functional Areas
Network Types
Stages
???? ?
Disciplines
Information Types
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????????
network
????
NM
...
Notification
RMON Device
RMON Device
Polling
Firewall / Router
...
Internet
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???????? (?)

• Polling (??)
• ??????????????????? ?
• ?????????,?????????,????515???
• Notification (??)
• ???????????,?????????????(Event Report)?