chapter 1 Flashcards
introduction
What is data communication?
The exchange or transfer of data/information between a source and a receiver.
What are the four fundamental characteristics of an effective data communication system?
- Delivery
- Accuracy
- Timeliness
- Jitter
Define ‘Delivery’ in the context of data communication.
The system must deliver data to the current destination intended device or user.
What does ‘Accuracy’ refer to in data communication?
The system must deliver data accurately; altered data during transmission is unusable.
Explain ‘Timeliness’ in data communication.
Data must be delivered in a timely manner; late data is useless.
What is ‘Jitter’?
Variation in packet arrival time; uneven delay in delivery of audio or video packets.
What are protocols in data communication?
Rules and regulations that allow computers with different systems to share resources.
List the five components of a communication system.
- Message
- Sender
- Receiver
- Transmission medium
- Protocol
What is a ‘Message’ in data communication?
The information (data) to be communicated, such as text, pictures, audio, and video.
Define ‘Sender’ in a communication system.
The device that sends the data message, e.g., computer, workstation, or telephone.
What is a ‘Receiver’ in data communication?
The device that receives the message, such as a computer, workstation, or television.
What is a ‘Transmission medium’?
The physical path by which a message travels from sender to receiver, e.g., cables or radio waves.
What is the purpose of network models?
To organize, unify, and control hardware and software components of data communication.
Name the two primary network models mentioned.
- OSI model (Open Systems Interconnection)
- Internet model (TCP/IP)
What are the two categories of network standards?
- De facto
- De jure
Define ‘De facto standards’.
Standards that are adopted through widespread use but not officially approved by an organized body.
What are ‘De jure standards’?
Standards that have been legislated by an officially organized body.
List some standards creation committees.
- International Organization for Standards (IOS)
- International Telecommunication Unit-Telecommunication (ITU-T)
- American National Standards Institute (ANSI)
- Institute of Electrical and Electronics Engineers (IEEE)
- Electronic Industries Association (EIA)
What is a communication link?
A pathway through which data is transferred between two or more communicating devices.
What is a ‘Point-to-point’ connection?
A dedicated link between two communicating devices.
Define ‘Multipoint connection’.
A connection where more than two specific devices share a single link.
What does ‘Topology’ refer to in networking?
The layout of a network, either physically or logically.
List the five basic topologies.
- Mesh topology
- Star topology
- Bus topology
- Ring topology
- Tree topology
What is ‘Mesh topology’?
Every device has a dedicated point-to-point link to every other device.
What are the advantages of Mesh topology?
- Guarantees data load capacity
- Does not incapacitate the entire system if one link fails
- Added privacy and security
- Easy fault identification & isolation
What is ‘Star topology’?
Each device has a dedicated point-to-point link to a central controller called a hub.
Define ‘Bus topology’.
A multipoint topology where one long cable acts as a backbone linking all devices.
What is ‘Ring topology’?
Each device has a point-to-point connection with the two devices on either side, passing signals in one direction.
What is ‘Tree topology’?
A variation of star topology where all nodes are linked to a central hub controlling traffic.
Name the three transmission modes.
- Simplex
- Half duplex
- Full duplex
What is ‘Simplex’ communication?
Unidirectional communication where only one device can transmit.
Define ‘Half duplex’ communication.
Each station can transmit and receive, but not at the same time.
What is ‘Full duplex’ communication?
Both stations can transmit and receive simultaneously.
List the categories of networks based on size and distance.
- Local Area Network (LAN)
- Wide Area Network (WAN)
- Metropolitan Area Network (MAN)
- Internetworks
What is a Local Area Network (LAN)?
A network that links devices in a single office, building, or campus, usually privately owned.
Define Wide Area Network (WAN).
A network providing long-distance transmission of data over large geographic areas.
What is a Metropolitan Area Network (MAN)?
A network covering an area inside a town or city, designed for high-speed connectivity.
What are Internetworks?
Networks that are interconnected, typically using routers or gateways.
