Introduction Reading Assignment : Stallings Chapter 1

1
IntroductionReading Assignment Stallings
Chapter 1

• A communication model
• Source
• e.g., telephone, computer
• Transmitter
• transforms and encodes the information to produce
  electromagnetic signals
• Transmission system
• a single transmission line or a complex network
• Receiver
• opposite of transmitter
• Destination
• Communication tasks
• Transmission system utilization
• interfacing
• signal generation
• synchronization
• exchange management
• error detection and correction
• flow control
• addressing

2

• routing
• recovery
• message formatting
• security
• network management
• Data communications networking
• networks vs. dedicated links
• Wide-area networks
• interconnecting / switching nodes
• circuit switching
• fixed data rate circuits
• dedicated path, minimal delay
• telephone network
• packet switching
• brief delay
• designed for older networks (64 kbps)
• overhead
• redundancy, addressing, error checking for high
  error rate of equipment
• computer to computer communication

3

• Integrated Service Digital Network (ISDN)
• intended to be a new worldwide digital
  telecommunication network
• all types of data
• narrowband ISDN frame relay technology
• broadband ISDN ATM
• Local-area networks
• small scope, single building / floor
• owned by single organization
• capital investment
• network management responsibilities
• broadcast network
• packets
• shared medium, only one station can transmit at a
  time
• Protocols and protocol architecture
• cooperation between source and destination
  entities in separate systems
• protocol
• convention of cooperation
• a set of rules governing the exchange of data
  between entities

4

• Protocol architecture
• simplified architecture for file transfer
• passwords, file commands
• reliability requirements
• network access
• Basic three-layer model
• application
• transport
• destination service access point (SAP)
• sequence number
• error-detection code
• network access
• destination computer address
• facilities requests priorities, etc.
• TCP/IP protocol architecture
• physical layer
• interface between computer and network
• transmission medium, nature of signals, data
  rate, etc.
• network access layer