Chapter 6: Data Communication: Delivering Information Anywhere & Anytime Flashcards
Data Communication
electronic transfer of data from one location to another
Bandwidth
amount of data that can be transferred from a location to another
Attenuation
loss of power in a signal as it travels from the sending device to receiving
Broadband
multiple pieces of data sent simultaneously
Narrowband
voice-grade transmission channel capable of transmitting maximum 56,000 bps
Protocols and 3 example
rules that govern data communication
1. error detection
2. message length
3. transmission speed
Data Communication System Components (3)
sender and receiver
communication medium
modems and routers
Forms of sender and receiver: Input/output device
sending and receiving information
Forms of sender and receiver: Smart Terminal
performs processing tasks but no full computer
Forms of sender and receiver: PC or ITerminal
remote computer performs processing tasks without main computers support
Forms of sender and receiver: Network Computer
etc mac-book, tablet, light weighted
Forms of sender and receiver: Midrange server or supercomputer
process data and send to other devices and receive data
Forms of sender and receiver: household devices
video games, smartphones, tv
Communication Media
connect sender and receiver devices
conducted media (4)
physical path, signals transmitted, twisted pair copper cable, fiber-optics
Radiated media
antenna for transmitting data through air or water
Diagram on communication media
slide 9 and 10
Modems and term short for
device that connects a user to internet
modulator demodulator
Modem - Dial up:
phone lines connect to the internet converts digital to analog data
Modem - Digital Subscriber
high speed service that uses phone lines
Modem - Cable
cables that connect to TV’s for internet connections
Modem - Fiber Optics
cable made of thin strands of glass/plastic - optical fibers
Types of Networks: LAN - Local Area Network
connects workstations and devices in close proximity to share resourcs
Types of Networks: WAN - Wide Area Network
connects workstations and devices across cities - countries, connect to other networks
Types of Networks: MAN - Metropolitan Area Network
communication for multiple organizations in nearby cities
Scope ranking of networks
WAN > MAN > LAN
Speed Ranking of networks
LAN > MAN > WAN
Network Typologies
network’s physical layout including arrangement of computers and cables
Star Topology (2)
central computer and series of nodes, host connection
Nodes
series of redistribution points or communication endpoints
Star Topology Advantages (2)
cable layouts easy to modify
centralized control makes detecting problems easier
Star Topology Advantages (2)
Single point of potential failure
increased cost due to many cables
Ring Topology
each computer manages its own connectivity so no host
Ring Topology - Nodes connection and transmission (2)
Each node is connected to other nodes
Bidirectional transmission
Ring Topology Advantages and Disadvantages
Advantages: Fault Tolerance
Disadvantages: Difficult diagnosing problems and modifying network
Bus Topology: cable and node layout (3)
Connects nodes along a network segment
ends of cables aren’t connected
terminator absorbs signal at each end
Bus Topology Node and Line Failure Effect
Node Failure has no effect on any other node
Line Failure has the entire network go down
Bus Topology Advantages (2)
easy to extend
wiring layout simple, uses least topology and keeps cost down
Bus Topology Disadvantages (2)
Fault diagnosis is difficult and data collisions
bus cable can be bottleneck when network traffic heavy
Hierarchical Topology (2)
- organization of computers depends on processing strength
- mainframe on top and clients on the bottom
Hierarchical Advantage and Disadvantage (2)
Advantage: network control
Disadvantage: Network expansion may be a problem and traffic congestion at root and high level nodes
Mesh Topology
Advantages
Disadvantages
- every node/computer is connected to other node/computer
- reliable and fault tolerant
- costly, difficult to maintain and expand
Router
network connection device (hardware) containing software that connects network systems and controls traffic flow (routing)
Centralized Routing
Distributed Routing
single node is charge of selecting path for all pockets
relies on each router node to calculate its own best possible route
Routing Table
generate automatically by software, best possible route for a router
Network Interface Card (NIC)
Hardware component enables computers to communicate over a network
Network Operating System (NOS)
specialized operating system for a network device such as a router, switch or firewall.
Protocols (3)
rules that electronic devices use to exchange information
hardware connections, control data transmission, file transfer
specify format of message packets sent between computers
Packet
binary digits sent from computer to computer over network
Open System Interconnection (OSI) Model
Seven Layer architecture for defining how data is transmitted in network
Layers of OSI and Description
- Application: Access network etc word, Excel, Chrome
- Presentation: Formats message packets
- Session: Communication connection w/ computers
- Transport: integrity of message
- Network: routes messages
- Data Link: Computer talk to each other (control of communication link)
- Physical: Topology connection for computer communication
ransmission Control Protocol/Internet Protocol (TCP/IP)
industry standard communication protocols across networks (runs the internet)
Transmission Control Protocol:
establishes link between hosts, ensures message integrity, sequencing, and acknowledging packet delivery, and regulates data flow between source and
destination nodes
Internet Protocol:
operates at the OSI model’s Network layer, and is
responsible for packet forwarding
