Chapter 6: Data Communication Flashcards
(28 cards)
Data Communication
Electronic transfer of data from one location to another
Bandwidth
The amount of data that can be transferred from one point to another in a certain time period, usually one second
Attenuation
Loss of power in a signal as it travels from the sending device to the receiving device
Broadband (data transmission)
Multiple pieces of data are sent simultaneously to increase the transmission rate
Narrowband
Voice-grade transmission channel capable of transmitting a maximum of 56,000 bps, so only a limited amount of information can be transferred
3 Major components of a data communication systems
1) Sender and receiver devices
2) Modems (devices that connect a user to the Internet) or routers (connects network systems and controls their traffic flow)
3) Communication media (connect sender and receiver devices)
Digital subscriber line (DSL)
A type of modem that uses ordinary phone lines
Communication Media/Channels
Connect sender and receiver devices
- Either conducted: Physical path that signals are transmitted or
- Radiated: Uses antenna
3 types of processing configurations
1) Centralized: One computer
2) Decentralized: Many computers
3) Distributed: Processing power is distributed among several locations
Network Interface Card (NIC)
- Hardware component that enables computers to communicate over a network
- Also called adapter card
3 Types of Networks
1) Local area network (LAN): Connects devices that are in close proximity
2) Wide area network (WAN): Spans serval cities, states, or countries and is owned by different parties
3) Metropolitan area network (MAN): Data communications for multiple organizations in a city or nearby cities
Network Topologies
Represent a network’s physical layout, including the arrangement of computers and cables
- Types: Star, ring, bus, hierarchical, mesh
Star Topology
Consists of a central computer (host computer or serve) and a series of nodes (workstations or peripheral devices)
Ring Topology
- No host computer is required as each computer manages its own connectivity
- Each node is connected to two other nodes
- Transmission in one direction
- Needs less cable than star topology
Bus Topology (linear bus)
Connects nodes along a network segment, but the ends of the cable are not connected, as they are in ring topology
Hierarchical Topology (tree)
Combines computers with different processing strengths in different organizational levels
- Consists of the controller: Hardware and software device that controls data transfer from a computer to a peripheral device
- And the multiplexer: Hardware device that allows several nodes to share one communication channel
Mesh Topology (plex/interconnected)
Every node is connected to every other node
- Known as plex or interconnected
Protocols
Rules that govern data communication/information exchange
- Ex: Error detection, message length, and transmission speed
Routing
The process of deciding which path data takes on a network.
- Usually determined by the type of network and the software used to transmit the data
- Routing table: Generated automatically by software and is used to determine the best possible route for a packet
Packet
A collection of binary digits (including message data and control characters for formatting and transmitting) sent from computer to computer over a network
2 types of routing
1) Centralized routing: One node is in charge of selecting the path for all packets. Stores routing table, does changes to a route
2) Distributed routing: Relies on each node to calculate its own best possible route. Each node contains its own routing tables
Router
A network connection device containing software that connects network systems and controls their traffic flow
- Chooses the best path for packets
2 Types of routers
1) Static: Require the network routing manager to give it information about which addresses are on which network
2) Dynamic: Build tables that identify addresses on each network
Client/Server Model
Software runs on the local computer and communicates with the remote server to request information or services
- A server is a remote computer on the network that provides information or services in response to client requests