Networks Flashcards
Module of Networks
What are networks?
Networks allow devices like computers, phones, and printers to connect and share information
They make communication easier and help people work together.
What is network topology?
The structure or layout of a network
The type of topology can affect network efficiency and expansion.
What is a communications network?
A vehicle for exchanging information, collaborating, and sharing access to various types of data
Data could include social media, music, audio, video, etc.
Describe Star Topology.
All devices are connected to a central hub
The hub manages communication between devices.
What are the advantages of Star Topology?
- If a device fails, the rest of the network continues functioning
- New devices can be added without affecting the network’s operation
- Reliable and scalable
What are the disadvantages of Star Topology?
- If the central hub fails, the entire network goes down
- The hub may become overloaded when too many devices are connected
Describe Bus Topology.
All devices are linked via a single central cable (the ‘bus’)
Data is transmitted along this shared cable.
What are the advantages of Bus Topology?
- Simple and inexpensive to set up
- New devices can be easily added
What are the disadvantages of Bus Topology?
- If the main cable fails, the entire network fails
- Network performance slows as more devices are added
Describe Ring Topology.
Devices are connected in a circular loop with data moving sequentially from one device to the next.
What are the advantages of Ring Topology?
- Equal opportunity for all devices to transmit data
- Predictable network behavior
What are the disadvantages of Ring Topology?
- A single device failure can disrupt the entire network
- Data transmission can be slower in larger networks
What is Token Ring?
A type of ring topology where a ‘token’ circulates around the network, allowing devices to transmit data only when they have the token.
What is Dual Ring Topology?
A variation of the ring topology with two rings for redundancy
If one ring fails, the other can still carry data.
Describe Mesh Topology.
Every device is connected to every other device, providing multiple paths for data to travel.
What are the advantages of Mesh Topology?
- Highly reliable with no single point of failure
- Data can be routed through alternative paths
What are the disadvantages of Mesh Topology?
- Expensive and complex to implement
- Requires multiple connections for every device
What is a collision in Bus Topology?
When multiple devices try to send data simultaneously on a shared line, a collision occurs.
How are collisions resolved in Bus Topology?
Devices wait for a random amount of time before trying to retransmit after a collision.
What is scalability in networking?
The ability to expand a network without significant issues.
What is a single point of failure?
A part of the network that, if it fails, can bring down the entire network.
Which topologies are cost and complexity effective in networking?
- Mesh networks are highly reliable but expensive
- Star and bus topologies are simpler and cheaper to implement
What are Wireless Networks?
Networks that use radio waves to transmit data without physical cables.
What is CSMA/CD?
Carrier Sense Multiple Access with Collision Detection, a protocol for managing data transmission over a shared medium.
What is TCP?
Transmission Control Protocol, a connection-oriented protocol ensuring reliable data transmission.
What is UDP?
User Datagram Protocol, a connectionless protocol that allows faster data transmission with less reliability.
What is a three-way handshake?
A process used by TCP to establish a connection between two devices: SYN, SYN-ACK, ACK.
What is Quality of Service (QoS)?
A measure that ensures certain applications receive higher priority for data transmission.
What is Power over Ethernet (PoE)?
A technology that allows Ethernet cables to carry both data and electrical power.
What are VLANs?
Virtual Local Area Networks used to logically segment a network for traffic management and security.
What is a Network Interface Card (NIC)?
A hardware component that connects a device to a network and has a unique MAC address.
What is IP addressing?
The method of assigning unique identifiers (IP addresses) to devices on a network.
What are common IP address classes?
- Class A: Up to ~16 million hosts
- Class B: Up to ~65,000 hosts
- Class C: Up to 254 hosts
What is DHCP?
Dynamic Host Configuration Protocol, which automatically assigns IP addresses to devices within a network.
What is ARP?
Address Resolution Protocol, used to map IP addresses to physical MAC addresses.
What are the components of a data packet?
- Source IP address
- Destination IP address
- Error-handling codes
- Flow control data
What is modulation?
The process of converting a digital signal into an analogue form for transmission.
What is the benefit of digital transmission?
Digital signals resist cumulative noise and offer higher efficiency and better error rates.
What does SONET stand for?
Synchronous Optical Networking, a high-speed networking standard.
What is the purpose of interoperability in networking?
Facilitate interoperability between different media types (e.g., fiber to Ethernet)
Interoperability ensures that different systems and technologies can work together seamlessly.
What are RS-232 and V.35 used for?
Widely used for connecting devices in networking setups
These interfaces are standard protocols for serial communication.
Describe RS-232.
A simple interface for lower-speed connections with one-wire circuits
RS-232 is suitable for short-distance communication.
Describe V.35.
High-speed connections with balanced two-wire circuits for data and timing
V.35 is commonly used in leased lines and high-speed data transmission.
What is multiplexing in networking?
Combines multiple data streams into one medium, increasing efficiency
This technique optimizes the use of available bandwidth.
What is Time-Division Multiplexing (TDM)?
Used in T1/E1 circuits to allocate fixed time slots for multiple channels
TDM allows several signals to share the same communication channel.
What does Dense Wavelength Division Multiplexing (DWDM) do?
Employed in fiber optics to support thousands of simultaneous transmissions
DWDM enhances the capacity of fiber networks.
What is Frame Relay?
Offers high-speed, cost-efficient alternatives to legacy systems like X.25
Frame Relay is used for wide area networking and operates at Layer 2 of the OSI model.
What is the role of Data Link Connection Identifiers (DLCIs) in Frame Relay?
For routing
DLCIs help in identifying virtual circuits in Frame Relay networks.
What are the characteristics of Asynchronous Transfer Mode (ATM)?
Uses fixed-size cells (53 bytes: 5-byte header, 48-byte payload) for predictable performance
ATM is suitable for real-time applications due to its low latency.
What modern advancements have been made in wireless networking?
Modern Wi-Fi standards (e.g., IEEE 802.11ax) provide faster speeds and improved reliability
These advancements enhance the performance of wireless networks.
What is a converged network?
Combining voice, video, and data over a single network infrastructure
Converged networks simplify management and reduce operational costs.
What is the OSI Reference Model?
Provides a framework for understanding how different networking layers interact
The OSI model consists of seven layers, each with specific functions.
What is the function of Layer 1 in the OSI model?
Manages hardware connections, such as cables and voltage levels
This layer is also known as the Physical layer.
What does Layer 2 of the OSI model do?
Ensures error-free data transfer between adjacent nodes and handles MAC addressing
Layer 2 is referred to as the Data Link layer.
What is the primary role of Layer 3 in the OSI model?
Handles packet forwarding and routing via IP addresses
This layer is known as the Network layer.
What does Layer 4 of the OSI model ensure?
Ensures reliable data delivery through protocols like TCP and UDP
Layer 4 is referred to as the Transport layer.
What is the function of Layer 5 in the OSI model?
Manages and synchronizes dialogue between two systems
This layer is known as the Session layer.
What does Layer 6 of the OSI model do?
Translates and formats data for the application layer; includes encryption
Layer 6 is referred to as the Presentation layer.
What is the role of Layer 7 in the OSI model?
Enabling email, file transfers, and network services
This layer is known as the Application layer.
