Discussion Board
smartman1212
IT340Chap1week02.ppt*
Chapter 1
Data Communications and
Network Management Overview
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Objectives
- Telecommunications overview
Data communications overview
Evolution of converged networks
Desktop processors and LAN technology
Client-Server architecture in networking
Internet and intranet
Network communication protocols
OSI and Internet standards
Broadband networks and services
Need for network management and NMS
Operations, Administration, Maintenance, and Provisioning
Network management architecture and organization
Concept of Network Operations Center
Perspectives of network management
Network management system
Look-ahead of network management technology
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Telephone Network
- Modern network evolution from Telephone /
Telecommunications Network - Characteristics of Telephone network
- Reliable - does what is expected of it
- Dependable - always there when you need it (remember 911?)
- Good quality (connection) - hearing each other well
- Reasons for QoS:
- Good planning, design, and implementation
- Good operation and management of network
- Migration to new technologies –
- e.g., From analog to digital technology
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Telephone Network Model
- Notice the hierarchy of switches
- 5 levels of switches and 3 types of trunks
- Loop: between telephone/PBX and end office
- Direct trunk between two end-offices
- Toll-connecting trunk: end office to any toll office
- Toll (internal) trunk: between toll offices
- Primary and secondary routes programmed
- Automatic routing
- Where is the most likely failure?
- Use of Operations Systems to ensure QoS
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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OSSs / NOC
- Operations Support Systems (OSSs) help manage the operation of networks
- OSSs in telecommunications monitor:
- Analog network parameters:
- S/N ratio, transmission loss, call blockage, etc.
- Digital network parameters:
- Packet loss, Packet delay, Throughput, QoS, etc.
- Real-time management of network
- Trunk (logical entity between switches / nodes) maintenance system measures loss and S/N Trunks not meeting QoS removed before customer notices poor quality
- Traffic measurement systems measure call drops and blockage. Additional switches or routers planned to keep the call blockage or drops below acceptable level
- OSSs distributed at central offices and customer premises
- Network management done centrally from Network Operations Center (NOC)
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Data and Telecommunication Network
- Computer data is carried over long distance by telephone (telecommunication network)
- Output of telephone is analog and output of computers is digital
- Modem is used to “modulate” and “demodulate” computer data to analog format and back
- Clear distinction between the two networks is getting fuzzier with modern multimedia networks
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Migration to Digital Technology
- Analog transmission migrated to digital transmission
- Analog sources converted to digital signals
- CPE (Customer Premises equipment) included digital PBX (Private Branch Exchanges)
- Analog bandwidth hierarchy migrated to synchronous digital hierarchy
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
DCE with LAN
DCE.. Distributed Computing Environment
- Driving technologies for DCE:
- Desktop processor
- LAN
- LAN - WAN network
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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LAN-WAN Network
- Major impacts of DCE:
- No more monopolistic service provider
- No centralized IT controller
- Hosts doing specialized function
- Client/Server architecture formed the core of DCE network
Figure 1.5(b) Remote LANs Interconnected by WAN
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Client/Server Model
- Post office analogy; clerk the server, and the customer the client
- Client always initiates requests
- Server always responds
- Notice that control is handed over to the receiving entity.
Request
Response
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Client/Server Examples
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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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
- Internet email and much of the network mgmt. messages are based on UDP/IP
- ICMP part of TCP/IP suite
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Internet Configuration
- Walk through the scenario of email from Joe to Sally
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Architecture, Protocols and Standards
- Communication architecture
- Modeling of communication systems, comprising
- Functional components
- 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
- Operational procedures
- Examples: (Students to call out)
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Communication Architecture
- Inter-layer interface: user and service provider
- Peer-layer protocol interface
- Analogy of hearing-impaired student
- Role of intermediate systems
- Gateway: Router with protocol conversion as gateway to an autonomous network or subnet
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
OSI Reference Model
- Importance of the knowledge of layer structure in NM
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
OSI Layers and Services
- Importance of services offered by different layers and the protocol conversion at different layers in NM
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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LayerNo.
Layer Name
Salient services provided by the layer
1
Physical
-Transfers to and gathers from the physical medium raw bit data
-Handles physical and electrical interfaces to the transmission medium
2
Data link
-Consists of two sublayers: Logical link control (LLC) and Media access control (MAC)
-LLC: Formats the data to go on the medium; performs error control and flow control
-MAC: Controls data transfer to and from LAN; resolves conflicts with other data on LAN
3
Network
Forms the switching / routing layer of the network
4
Transport
-Multiplexing and de-multiplexing of messages from applications
-Acts as a transparent layer to applications and thus isolates them from the transport system layers
-Makes and breaks connections for connection-oriented communications
-Flow control of data in both directions
5
Session
-Establishes and clears sessions for applications, and thus minimizes loss of data during large data exchange
6
Presentation
-Provides a set of standard protocols so that the display would be transparent to syntax of the application
-Data encryption and decryption
7
Application
-Provides application specific protocols for each specific application and each specific transport protocol system
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Notes
PDU Communication Model
- What is the relevance of PDU model in NM?
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Gateway
- cc: mail from a station in Novel IPX network to an Internet station with SMTP email
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
OSI and Internet
- Simplicity of Internet; specifies only layers 3 and 4
- Integrated application layers over Internet
- Commonality of layers 1 and 2 - IEEE standard
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Application Protocols
Internet user OSI user
Telnet Virtual Terminal
File Transfer Protocol File Transfer Access & Mgmt
Simple Mail Transfer Message-oriented Text
Protocol Interchange Standard
Simple Network Common Management
Management Protocol Information Protocol
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Broadband Network
Chapter 1 Data Communications and NM Overview
Figure 1.19 Broadband Network Segments and Technologies
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Broadband Access Networks
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Centrally Managed Network Issues
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
- INMS: Integrated Network Management System
- EMS: Element Management System
- INMS integrates alarms from multiple EMSs
- Each EMS manages a domain and passes the relevant events to the INMS
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Some Common Network Problems
- Loss of connectivity (connectivity and node failures)
- Duplicate IP address
- (e.g. with multiple system administrators)
- Intermittent problems
- Network configuration issues
- E.g. Power hit default configuration
- Non-problems
- The cause of failure is a mystery
- Performance problems
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
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”
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Network Management
- OAMP
- Operations
- Administration
- Administrate overall goals, policies, and procedures of NM
- Maintenance
- Provisioning
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
NM Functional Flow Chart
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
- NOC is responsible for service restoration when failure
- Self-healing: when restoration is done automatically
- Restoration does not include fixing the cause of the problem
- I&M responsibility
- A Trouble Ticket is generated and followed up for problem resolution
- Configuration management: static, running, and planning
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Dumbbell Architecture
- Message exchange between NMSs managing different domains
- Management information data (type, id, status of managed objects)
- and management controls (setting and changing configuration of an object)
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
- Network management vs Network system and service management
- Network management is concerned with network equipment and the connectivity among them
- Network system and service management: manage the system resources in the network and network services
- May need installation/integration of multiple NMSs
- Standards for interoperability
- Network management dumbbell architecture for interoperability
- Application services: e.g. fault and configuration management
- Management protocols: e.g. CMIP and SNMP
- Transport protocols: first 4 layers of OSI and first 2 layers of Internet model
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NM Components
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
- The agent can be:
- An embedded agent in a network element
- EMS communicating with agents embedded in the network elements
- The agent communicates to the NMS the relevant data
- Response to a polled query from the NMS
- Triggered by a local alarm
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Interoperability
- Message exchange between NMSs managing
different domains
Figure 1.26 Network Management Interoperability
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
- Each NMS can superimpose the data from the other
- Present an integrated picture to the network administrator
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Network Management Perspectives
- Network Management
- Domains (based on geographic, vendor, technology) + protocols + network and transmission technologies
- Service Management
- QoS parameters + SLA between service provider and customer
- Communication services: internet, Virtual Private Network, real-time interactive audio and video services, etc. monitor system resources and applications that run on them
- Service and Network Provisioning
- Application Management
- e-Commerce Management
- Inventory Management
- Inventory of equipment (active components forming nodes of the network) and facilities (passive components linking the nodes)
- Integrated Management
- Business Management
- Information Management
- Management Protocols
- Management Technologies
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Infrastructure Perspective
- Domains
- Protocols
- Technologies
- Transmission Media
- Transmission Modes
- Service Functions
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Service Perspective
- Communication Services
- Computing Services
- Content Services
- IT Services
- Application Services
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Notes
Status and Future Trends
- Status:
- SNMP management
- Limitations: Poll-based + use of scalar values
- Limited CMIP management
- Object-oriented but complexity of specifications of managed objects
- Operations systems
- UNIX for high-end systems
- Polled systems
- Network traffic overhead
- Current Focus:
- Object-oriented approach
- Service and policy management
- Business management
- Web-based client management
- Future Trends
- Web-based management?
- XML based management
Chapter 1 Data Communications and NM Overview
Network Management: Principles and Practice
© Mani Subramanian 2010
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Regional Center
Class 1 switch
Sectional Center
Class 2 switch
Primary Center
Class 3 switch
Toll Center
Class 4 switch
End Office
Class 5 switch
Regional Center
Class 1 switch
Sectional Center
Class 2 switch
Primary Center
Class 3 switch
Toll Center
Class 4 switch
End Office
Class 5 switch
Voice
Voice
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
Figure 1.1 Telephone Network Model
Legend:
Loop
Direct Trunk
Toll-Connecting Trunk
Toll Trunk
Terminal
Modem
Voice
Terminal
Modem
Modem
Voice
Host
Data communication network
Telecommunication network
Figure 1.3 Data and Telecommunication Networks
Loop
Loop
Loop
Terminal
Communications
controller
Terminal
Front end
processor
Host
Data communication network
Telecommunication network
Figure 1.4 Digital Data and Telecommunication Networks
PBX
Voice
PBX
Voice
Voice
Voice
Ethernet
Workstation
Workstation
Host
Host
Workstation
Fgure 1.5(a) Hosts and Workstations on Local LAN
LAN A
LAN B
LAN C
Bridge /
Router
Bridge /
Router
Bridge /
Router
WAN
communication link
Client
Server
Control
transfer
Control
transfer
Figure 1.6 Simple Client-Server Model
Client A
Client Z
Server
(a) Server with Multiple Clients
Client
(joe.stone)
Domain
Name
Server
Mail server
(b) Dual Role of Client-Server
Figure 1.7 Client-Server in Distributed Computing Environment
Bridge
LAN A
LAN B
LAN C
Bridge /
Router
Bridge /
Router
Bridge /
Router
LAN Y
LAN Z
LAN X
Bridge /
Router
Bridge /
Router
Bridge /
Router
WAN
Workstation
Mail Server
Figure 1.8 Internet Configuration
Mail Server
Workstation
Gateway
Gateway
Domain
Name
Server
Workstation
(Joe)
PC (Sally)
User A
Application Layers
Transport Layers
User Z
Application Layers
Transport Layers
Physical Medium
Peer-Protocol Interface
(a) Direct Communication between End Systems
User A
Application Layers
Transport Layers
User Z
Application Layers
Transport Layers
Physical Medium
Peer-Protocol Interface
(b) Communication between End Systems via an Intermediate System
Transport Layer
Conversion
Figure 1.10 Basic Communication Architecture
System A
Intermediate system
System Z
Physical Medium
User / Application program
Application
Layer 7
Presentation
Layer 6
Session
Layer 5
Transport
Layer 4
Network
Layer 3
Data link
Layer 2
Physical
Layer 1
Physical medium
Figure 1.11 OSI Protocol Layers
Layer
No.
Layer Name
Salient services provided by the layer
1
Physical
-Transfers to and gathers from the physical medium raw
bit data
-Handles physical and electrical interfaces to the
transmission medium
2
Data link
-Consists of two sublayers: Logical link control (LLC) and
Media access control (MAC)
-LLC: Formats the data to go on the medium; performs
error control and flow control
-MAC: Controls data transfer to and from LAN; resolves
conflicts with other data on LAN
3
Network
Forms the switching / routing layer of the network
4
Transport
-Multiplexing and de-multiplexing of messages from
applications
-Acts as a transparent layer to applications and thus
isolates them from the transport system layers
-Makes and breaks connections for connection-oriented
communications
-Flow control of data in both directions
5
Session
-Establishes and clears sessions for applications, and
thus minimizes loss of data during large data exchange
6
Presentation
-Provides a set of standard protocols so that the display
would be transparent to syntax of the application
-Data encryption and decryption
7
Application
-Provides application specific protocols for each specific
application and each specific transport protocol system
User A
Application
End System A
Physical Medium
Figure 1.13 PDU Communication Model between End Systems
Presentation
Session
Transport
Network
Data link
Physical
User Z
Application
End System Z
Presentation
Session
Transport
Network
Data link
Physical
UD
(A) PCI
(P) PCI
(A) PDU
(S) PCI
(N) PCI
(T) PCI
(P) PDU
(S) PDU
(D) PCI
(T) PDU
(N) PDU
UD
(D)PDU Data stream
SNICP
SNDCP
SNDAP
Transport
Data link
SNICP
SNDCP-SN
SNDAP-SN
Transport
Data link-SN
SNDCP-SN
SNDAP-SN
Transport
Data link
SNICP
SNDCP
SNDAP
Physical-SN
Data link-SN
Physical
Physical-SN
Physical
Subnetwork Medium
Network Medium
System A
Gateway System N
Subnet system N1
N
Z
A
N1
N2
N3
DTE-N1
DTE-A
A-N-Z Standard Network
N-N1-N2-N3 Subnetwork under Node N
(a) Network configuration
(b) Protocol Communication
Figure 1.16 Gateway Communication to Private Subnetwork
Application
Presentation
Session
Transport
Network
SNICP
SNDCP
SNDAP
Data Link
Physical
Application Specific
Protocols
Transport
Connection-
less: UDP
Connection-
oriented: TCP
Network
IP
Not Specified
OSI
INTERNET
Figure 1.17 Comparison of OSI and Internet Protocol Layer Models
OSI User
VT
FTAM
MOTIS
CMIP
SNMP
SMTP
FTP
Terminal
Application
File Transfer
Mail / Message
Transfer
Management
Application
Presentation Layer
Transport Layer
TELNET
Internet User
Figure 1.18 Application Specific Protocols in ISO and Internet Models
Edge
Router
Cable
DSL
Fixed
Wireless
Mobile
Wireless
Satellite
PON
Residential
Gateway
LAN
WLAN
HomePlug
Bluetooth
HomePNA
Cable
Access
Network
CPE
Network
IP
ATM
WAN
UWB
Firewire
MPLS
IP / ATM
WAN
Business
Customers
Cable Modem
Customer
Network
OC-n /
STS-n
Link
HFC
Network
Cable
Modem
DSL
Customer
Network
xDSL
Modem
Telephone
Loop
Fixed
Wireless
Customer
Network
Cable
Modem
Head End
Central
Office
Equipment
Router/
ATM Switch
Router/
ATM Switch
Terrestrial
Wireless
Satellite Communication
Access
Point
Network
Mobile
Unit
BSU
G-3 Wireless
BSU
Figue 1.20 Broadband Access Networks
EMS
Network
Element
Domain
EMS
Network
Element
Domain
EMS
Network
Element
Domain
INMS
Figure 1.21 Case History 2:
Centrally Managed Network Issues
Network
Management
Network
Provisioning
Network
Operations
Network
Maintenance
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 1.22 Network Management Functional Groupings
Engineering Group
- Network Planning &
Design
Operations Group
NOC
- Network Operations
I
& M Group
-Network Installation &
Maintenance
Fault TT
Configuration Data
TT Restoration
Performance & Traffic Data
Installation
Figure 1.23 Network Management Functional Flow Chart
New
Technology
Network
Users
Management
Decision
Vendor A
(b) Services and Protocols
Application
Services
Management
Protocol
Transport
Protocols
Objects
Objects
Vendor B
Objects
Objects
Figure 1.24 Network Management Dumbbell Architecture
NMS
Network
Agent
Network
Agent
Network
Objects
Network
Objects
Figure 1.25 Network Management Components
NMS
Vendor A
Network
Agent
Network
Agent
Network
Objects
Network
Objects
NMS
Vendor B
Network
Agent
Network
Agent
Network
Objects
Network
Objects
Messages
Services & Protocols
