Chapter 1 Introduction to Computer Networks and Data
Download
Report
Transcript Chapter 1 Introduction to Computer Networks and Data
Chapter 1
Introduction to Computer
Networks and Data
Communications
Communication
The transmission of a signal by way of a
medium from sender to receiver
Sender
Signal
Receiver
Transmission
medium
2
Communication Problems
Completeness & comprehension
Attenuation & noises
Competing resources
Routing & addressing
Security
3
Networks
Computer network
Voice network
Data network
Local area network
Metropolitan area network
Wide area network
Personal area network
Network management
4
Data Communications
Data Communications:
The movement of computer information (data)
from one point to another by means of electrical
or optical transmission systems
Is a sub-field of telecommunications
Telecommunications:
Includes the transmission of voice and video as
well as data
5
Network Configurations
Microcomputer-to-local area network
Microcomputer-to-Internet
Local area network-to-local area network
Personal area network-to-workstation
Local area network-to-metropolitan area network
Local area network-to-wide area network
Wide area network-to-wide area network
Sensor-to-local area network
Satellite and microwave
Cell phones
Terminal/microcomputer-to-mainframe computer
6
Convergence
An Additional Basic Connection – telephone-
to-network
Telephone systems are ubiquitous and now carry
more data than voice
Common configuration – telephone connected to
POTS
Newer configuration (VoIP) – telephone-to-LAN
via gateway or telephone to gateway via
DSL/cable
7
Network Components
Hardware
Computer
Network Interface Card (NIC)
Hub
Switch
Bridge
Router
Software
Network protocols
8
Network Architectures
A reference model that describes the layers of
hardware and software necessary to transmit data
between two points or for multiple devices /
applications to interoperate
Reference models are necessary to increase
likelihood that different components from different
manufacturers will converse
Two models to learn: OSI model and TCP/IP
protocol suite
9
The OSI Model
Application
(7) User input to host
Presentation
(6) Data coding, formatting
Session
(5) Begin, frames, end, rules
Transport
(4) End-to-end delivery
Network
(3) Message routing
Datalink
(2) Frame formatting, error
Physical
(1) Physical connections
10
OSI vs. The Internet
Application
Application
Application
Transport
Transport
Transport
Network
Network
Network
Presentation
Session
Datalink
Physical
Interface
Network Access
Physical
11
Logical vs. Physical Connection
Application
Application
Presentation
Presentation
Session
Session
Transport
Transport
Network
Network
Datalink
Datalink
Physical
Physical
12
13