1.0 Explaining Network Topologies Flashcards
Full-duplex
Bidirectional, simultaneous transmission.
Duplex
Bidirectional data flow.
Half Duplex
Bidirectional, non-simultaneous transmission.
VPN (Virtual Private Network):
A VPN creates a secure, encrypted connection over a public network, allowing remote access to a private network.
VLAN (Virtual Local Area Network):
VLANs are like creating separate virtual networks on the same physical network.
Host
Any Device on a network that can send or receive data(e.g., computers, servers, routers).
Datagram
A datagram is a self-contained, independent packet of data sent over a network.
Client
A device or software that request services from a server(e.g., a web browser accessing a website).
OSI Model
A 7-layer framework for network communication:
1. Physical – Transmits raw data.
2. Data Link – MAC addresses, frames.
3. Network – IP addressing, routing.
4. Transport – Reliable delivery (TCP/UDP).
5. Session – Manages connections.
6. Presentation – Formats, encrypts data.
7. Application – User-facing protocols (HTTP, FTP).
Physical Layer (L1)
Transfers raw bits over a medium.
-Cables,fiber optics, radio waves.
- Devices: Hubs, repeaters, network adapters
Data Link Layer (L2)
Frames data, manages MAC addresses, and detects errors in Ethernet, Wi-Fi, VLANs, and ARP using switches, NICs, and bridges.
Network Layer (3)
Routes packets using IP addresses.
- IP, ICMP, subnets, routing tables
- Devices: Routers, layer 3 switches
Transport Layer (L4)
Reliable, ordered data delivery between applications using port numbers.
Session Layer(L5)
Manages the establishment, maintenance, and termination of communication between devices. (Function)
*Authentication, API sessions, handshakes.(Process/ Example)
* Devices : Proxies, session managers (Device/Software)
Function: What the Session Layer does.
• Processes/Examples: How it does it (specific mechanisms).
• Devices/Software: What performs these functions
Presentation Layer (6)
Formats, encrypts, and compresses data.
*SSL/TLS, ASCII, Unicode, MIME.
* Devices: Codecs, encryption appliances.
Encapsulation (Packing Data)
Encapsulation is the process of adding headers to data as it moves through network layers. Each layer wraps the data with extra information needed for delivery.
Application Layer(L7)
Interfaces with user applications and services.
- HTTP, FTP, SMTP, IMAP
- Devices: Web servers, email clients, browsers.
Protocol Data Unit (PDU)
A chunk of data that is formatted and processed at each layer of the OSI model as it moves through the network.
Decapsulation (Unpacking Data)
Decapsulation is like unwrapping layers of packaging to get to the actual message (the data).
Adjacent Layer Interaction
Adjacent layer interaction is when each network layer passes information directly up or down to the layer next to it.
Cabled
: Physical connections between nodes, like copper or fiber optic cables. Also called bounded media.
Wireless
Communication without wires, using radio waves in the air.” (Specifically mentions radio waves and air as the medium)
Node:
A device (e.g., computer, router) connected to a network.
Physical Topology
The layout of network connections, often divided into segments for better performance and security.