Topic 1 A Review on Computer Networks (1) Flashcards
What are the disadvantages of a Metropolitan Area Network (MAN)?
Higher setup and maintenance costs, security risks, limited coverage, network congestion
Security risks require strong cybersecurity measures. Limited coverage does not extend beyond a city or metropolitan region.
What is a Wide Area Network (WAN)?
A network that extends over a large geographical area such as states or countries
WANs connect multiple smaller networks like LANs and MANs.
What are the characteristics of a Wide Area Network (WAN)?
- Large geographic coverage
- Uses public and private infrastructure
- Centralized management
- Supports remote access
List examples of Wide Area Networks (WAN).
- The Internet
- Banking networks
- Corporate WANs
- Government networks
What are the advantages of a Wide Area Network (WAN)?
- Large geographic coverage
- Centralized data and resources
- Scalability
- Supports Cloud Computing
- Enhances communication
- Reliable and redundant
- Remote access
What are the disadvantages of a Wide Area Network (WAN)?
- Security issues
- High setup cost
- Troubleshooting problems
- Slower speeds
- Complex management
What is defined as internetworking?
Two or more computer networks (LANs or WANs) connected using devices configured by a local addressing scheme.
What is an extranet?
A communication network based on the internet protocol used for information sharing, restricted to users with login credentials.
What is an intranet?
A private network based on the internet protocol accessible only by an organization’s employees.
What are the advantages of intranets?
- Communication
- Time-saving
- Collaboration
- Platform independency
- Cost effective
What is topology in computer networks?
The way computers and devices are connected, defining the structure of the network.
What are the two types of topology?
- Physical topology
- Logical topology
What defines physical topology?
The layout of devices in the network and how they are physically connected.
What are the advantages of a Metropolitan Area Network (MAN)?
- Covers a wide area efficiently
- High-speed data transfer
- Cost-effective for organizations
- Supports multiple users and businesses
- Improves communication and collaboration
What is a Local Area Network (LAN)?
A group of computers connected to each other in a small area such as a building or office.
What is a Personal Area Network (PAN)?
A network arranged within an individual person, typically within a range of 10 meters.
What are the advantages of Bus topology?
- Low-cost cable
- Moderate data speeds
- Limited failure impact
- Easy to expand
What is Star topology?
An arrangement where every node is connected to a central hub or switch.
What are the disadvantages of Star topology?
Central point of failure if the hub or switch goes down.
What is Ring topology?
A network where each computer and device are connected in a large circle.
What is token passing?
A network access method where a token circulates, allowing nodes to send messages.
What are the disadvantages of Ring topology?
- Failure in any device disrupts the entire network
- Performance degrades with more devices
- Communication delay increases with more nodes
What are the disadvantages of computer networks?
- Security risks
- High setup and maintenance costs
- Network failures affect many users
- Privacy issues
- Spread of viruses/malware
- Requires skilled personnel
- Bandwidth and performance issues
- Risk of data loss
What are the benefits of computer networks?
- File sharing
- Device sharing
- Service sharing
- Improved communication
- Cost efficiency
- Remote access
- Faster data transfer
- Security & backup
- Scalability
- Reliability & redundancy
What is the purpose of inserting a token in an empty frame?
To change a 0 to a 1 in the token bit part of the frame and insert a message with a destination identifier
This process allows workstations to identify and receive messages intended for them.
What happens when a workstation receives a message in a token-based network?
It copies the message and changes the token back to 0
This indicates that the message has been received.
Define ring topology.
A topology where each node is connected to two other nodes, forming a continuous loop
Data flows in one direction in a ring topology.
What is a key characteristic of data flow in ring topology?
Data flows in a clockwise direction in a continuous loop
This topology is unidirectional.
What are two security risks of ring topology?
- Easy interception of data
- Network failures affect all devices
List examples of physical topologies.
- Point to Point Topology
- Bus Topology
- Ring Topology
- Star Topology
- Mesh Topology
- Tree Topology
- Hybrid Topology
What is mesh topology?
An arrangement where computers are interconnected through various redundant connections
It allows multiple paths for data transmission.
What is a primary benefit of mesh topology?
High reliability due to multiple alternative paths for data
If one link fails, communication remains unaffected.
What is a disadvantage of mesh topology?
High cost due to many connected devices and transmission media
Management can also be difficult due to the network’s size.
Describe bus topology.
A topology where all stations are connected through a single backbone cable
Messages are broadcast to all stations.
What access method is commonly used in bus topology?
CSMA (Carrier Sense Multiple Access)
It helps control data flow to maintain integrity.
What are the two methods of CSMA?
- CSMA/CD (Collision Detection)
- CSMA/CA (Collision Avoidance)
In what situation is CSMA/CD used?
In physical bus topology
It detects collisions and stops transmission upon detection.
What is the maximum data transfer speed in bus topology?
10 Mbps
Achievable with coaxial cables.
Define hybrid topology.
A combination of various different topologies
It results when different topologies are interconnected.
What are the advantages of hybrid topology?
- Flexibility to combine strengths of various topologies
- Suitable for large or complex networks
What is a main disadvantage of tree topology?
Failure in the central device or main cable can disrupt the entire network
This highlights the dependency on central components.
What is the top-most node in tree topology called?
Root node
All other nodes are its descendants in a hierarchical structure.
What is a key advantage of tree topology?
Easily expandable
New devices can be added without significant disruption.
