Transcript Chapter 3 Telecommunication Architectures and Standard

Chapter 3
Telecommunication
Architectures and Standard
Agenda
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Network architectures & standards
Standard-making organizations
Pros and cons of standards
Open System Interconnection Model (OSI)
TCP/IP
Manufacturer architecture
Pros and cons of architecture
Network Architectures
• Design principles for
– Functions
– Data format
– Procedures
• Describe “what”
Communication Standards
• Rules for compatibility
• Specify “how”
Needs for Architectures and
Standards
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Complex communication systems
Maintenance and future growth
Connectivity between network devices
Distributed processing systems
Diagnostic and performance management
Standards-Making Organizations
• International Telecommunications UnionTelecommunication Standardization Section (ITUT)
• International Organization for Standardization
(ISO)
• American National Standard Institute (ANSI)
• Electrical Industries Association (EIA)
• National Institute of Standards and Technology
(NIST)
• Institute of Electrical and Electronic Engineers
(IEEE)
Standards
• V.
– Connection of digital equipment to telephone
analog line
• X.
– Connection of digital equipment to telephone
digital line
– X.400
• Allow communication between incompatible
electronic mail systems
– X.500
• Create and maintain a directory of e-mail users and
their network addresses
Pros and Cons of Standards
• Pros
– Compatibility between vendors
– Fewer products
• Cons
– Slow processing
– Obsolescence
– Freezing technology
– Discouraging innovation
Open System Interconnection Model
• International Organization for Standardization
• Interconnection of Dissimilar Network
• Seven Layers
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Application
Presentation
Session Control
Transport Control
Network Control
Data Link Control
Physical Link Control
Application Layer
• Determine data to be send at originating end
• Process data at receiving end
Presentation Layer
• Change data format
• Compression/expansion
• Encryption/decryption
Session Control Layer
• Communication rules
• Rate of transmission
• Accounting functions
Transport Control Layer
• Identify receiving address
• Calculate and check checksum of entire
message
Network Control Layer
• Route message
• Dissemble and assemble data (transmission
unit)
• Accounting functions
Data Link Control Unit
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Determine line usage
Establish link between two ends
Detect and correct transmission error
Add header and trailer
Divide data unit for transmission
Physical Link Control Layer
• Hardware specification
• Electrical characteristics
TCP/IP Protocol
• Transmission Control Protocol/Internet
Protocol
• Advanced Research Project Agency
• ARPANET
TCP/IP Structure
• Application layer
– User application
• Transport layer (TCP protocol)
– Communication, error-checking procedure
• Internet layer (IP protocol)
– Routing
• Network access layer
– Connection
• Physical
– Physical & electrical interface
Manufacturers’ Architecture
• Objectives
– Base for future products
– Control customers
• Types
– IBM: Systems Network Architecture (SNA)
– Digital Equipment Corporation: Digital
Network Architecture (DNA)
Pros and Cons of Layered
Architectures
• Pros
– Modularize structure for simplify maintenance
– Specify interfaces for easy change & future
growth
• Cons
– Complex Rules
– Cost of sophisticated intelligence
– Complex software
Points to Remember
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Network architectures & standards
Standard-making organizations
Pros and cons of standards
Open System Interconnection Model (OSI)
TCP/IP
Manufacturer architecture
Pros and cons of architecture
Discussion
• What are your thoughts on selecting
network equipment for an organization?