Transcript Chapter 1: Introduction

William Stallings
Business Data Communications
6th Edition
Chapter 1: Introduction
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Information & Communication
• Networking is critical to the new corporate
structures emerging in today’s businesses
• Benefits of good networks
– make geographically dispersed companies more
manageable
– help top-heavy companies trim down middle
management
– help companies break down barriers between
divisions.
– make automation and quality enforcement easier to
implement.
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Basic Communications Model
Source: Generates data to be transmitted
Transmitter: Converts data into transmittable
signals
Transmission System: Carries data
Receiver: Converts received signal into data
Destination: Takes incoming data
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Basic Communications Model
• Example
– Communication between a workstation and a
server
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Trends Driving
Data Communication
• Traffic growth
– Voice & data over Internet Protocol (IP); local
and long distance
• Development of new services
– Multimedia on demand and TV distribution
• Advances in technology
– Encourage and support increased growth and
new developments
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Key Technology Trends
• Faster and cheaper computing platforms,
communications hardware, and software
• Increasingly “intelligent” networks,
management and assessment tools
• Growing importance of Internet, intranet
and extranet applications
• Increasing use of and dependence on
mobile and wireless technology
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Enterprise Networks Drivers
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Enterprise Networks Convergence
A Three-Layer Model
1. Applications: Seen by end users
–
–
Voice calling, email, and instant messaging
Group collaboration and relationship management
2. Enterprise Services: Seen by network Manager
–
–
3.
Design, maintenance, and support services
Authentication, capacity management, and QoS
Infrastructure: Enterprise available assets
–
–
Links, LANs, WANs, and Internet connections
Carry information over data networks
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Unified Communication (UC)
Convergence
Web 2.0: Second generation web capabilities
1.
2.
User generated content (blogs, wikis, clips, etc.)
Desktop –like user interface friendly capabilities
Real-Time Communication (RTC): desktop and mobile
software clients functionalities
IP Enabling Contact Centers: Enhance customer contact
center functionality and performance
IP Mobility: Remote access technology and mobile employees
support
IP Wireless: IP packet extended to support local and wide area
wireless communication
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Business Information
Requirements
Personal, Workgroup, and Enterprise
Unified Integrated Communications:
• Voice communications
• Data communications
• Image communications
• Video communications
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The Internet and
Distributed Applications
Internet: a key infrastructure for supporting
distributed applications
TCP/IP: standard open architecture protocol suite
universally used in data networks
Distributed Applications: used in intercompany and
intra-company information exchange
Client-Server & Intranets: easy to implement
approach to most business applications
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Network Types
• Local Area Networks (LANs)
• Wide Area Networks (WANs)
–
–
–
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Circuit Switched
Packet Switched
Frame Relay
ATM
• Wireless Networks
• Metropolitan Area Networks (MANs)
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Simplified Network Model
WAN
LAN
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Networking Configuration
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Transmission of Information
• Transmission
- converts data into transmittable signals
• Transmission Media
- twisted pair, fiber, wireless, and coax
• Communication Techniques
- encoding, interface, protocols
• Transmission efficiency
- multiplexing, compression
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Management Issues
• Network Security
– Confidentiality
– Integrity
– Availability
• Network Management
–
–
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Highly distributed peer-to-peer networks
Complexity of managing and maintaining
Reliable operation at all times
Skilled personnel and communication costs
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Communications Standards
• Importance
– Choice of vendors and products
– Competition leads to lower cost
– Enovation through open standards
• Organizations
– Internet Society (ISOC), International Organization
for Standardization (ISO), the IEEE 802 LAN/MAN
Committee, the international Telecommunication
Union (ITU), and the National Institute of Standards
and Technology (NIST),
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Resources
• Book Web Site
– http://williamstallings.com
• Usenet Newsgroups
– IEEE Standards in Education
– No Jitter
– ZDNet
• Journals
– Business-oriented
– Technical
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