Further Network Architecture & Concepts

1. Network Devices

Hub

Hubs operate at the physical layer (Layer 1) of the OSI model. They are used to connect multiple devices in a local area network (LAN). Hubs simply broadcast data to all devices connected to them. They don’t have the intelligence to filter or direct data based on the destination address.

Switch

Switches operate at the data link layer (Layer 2) of the OSI model. Switches are used to connect multiple devices in a LAN. Unlike hubs, switches are more intelligent. They learn the MAC addresses of connected devices and forward data only to the specific device it is intended for, reducing network traffic and increasing efficiency.

Router

Routers operate at the network layer (Layer 3) of the OSI model. Routers are used to connect different networks (e.g., LANs or the Internet) and enable communication between them. Routers use IP addresses to determine the best path for data to travel between networks. They make decisions based on routing tables, allowing for efficient and secure data transmission.

Video – Simple explanation of network devices

 

2. What is a network architecture

Network architecture refers to the design and structure of a computer network. It encompasses the arrangement and interconnection of various components, such as hardware, software, protocols, and communication channels, to facilitate the efficient and secure exchange of information within a network. Network architecture serves as a blueprint or framework that guides the organization and operation of a network. Key elements of network architecture include:

• Topology: The physical or logical layout of the network, defining how devices are connected and the paths data takes.
• Protocols: A set of rules and conventions that govern communication between devices in the network. This includes standards for data transmission, error detection and correction, and network management.
• Hardware Components: The physical devices that make up the network, such as computers, servers, routers, switches, and cables. 
• Software Components: The programs and applications that enable communication, security, and management of network resources.
• Addressing Scheme: A method for identifying and addressing devices on the network, such as IP addresses in the case of Internet Protocol (IP) networks.
• Security Measures: Mechanisms and protocols in place to protect the network from unauthorized access, data breaches, and other security threats.
• Scalability: The ability of the network to accommodate growth in terms of the number of devices and the volume of data traffic.
• Reliability and Redundancy: Measures in place to ensure network availability and minimize downtime, often achieved through redundant components and failover mechanisms.
• Performance Optimization: Strategies to enhance the speed and efficiency of data transmission within the network.

Some Videos on Network Architectures

 

3. What is a VLAN

A VLAN, or Virtual Local Area Network, is a network segmentation and management technique that enables the creation of multiple logically segmented networks within a single physical network. VLANs are used to enhance network performance, security, and manageability by grouping devices together based on factors such as department, function, or project, regardless of their physical location.

Key characteristics and features of VLANs include:

• Logical Segmentation: VLANs create virtual networks within a physical network infrastructure. Devices within the same VLAN can communicate with each other as if they were on the same physical network, even if they are physically located in different areas.
• Isolation: Devices in one VLAN are isolated from devices in other VLANs, providing a level of security by preventing direct communication between certain groups of devices.
• Broadcast Control: VLANs help control broadcast traffic by confining broadcast and multicast traffic to the VLAN in which the broadcast originated. This reduces unnecessary traffic on the network and improves overall efficiency.
• Performance Optimization: VLANs can be used to optimize network performance by segregating high-traffic groups or applications into their own VLANs, preventing them from affecting the performance of other parts of the network.
• Inter-VLAN Routing: While VLANs keep traffic isolated within their own segment, routers are typically used to enable communication between different VLANs. This allows for controlled and secure communication between specific VLANs.

Video on VLAN

4. What is a VPN

A VPN, or Virtual Private Network, is a technology that provides a secure and encrypted connection over the internet, allowing users to access a private network from a remote location as if they were directly connected to that network locally. VPNs are commonly used to enhance privacy, security, and anonymity while accessing the internet or connecting to private corporate networks.

Key characteristics and functions of VPNs include:

• They use encryption protocols to secure the data transmitted between the user’s device and the VPN server. This ensures that even if the data is intercepted, it is unreadable without the appropriate decryption key.
• By encrypting internet traffic, VPNs help protect users’ online activities from surveillance and data interception. VPNs can also mask the user’s IP address, providing a degree of anonymity.
• VPNs enable remote users to connect securely to a private network over the internet. This is particularly useful for employees working from home or traveling, allowing them to access resources as if they were physically present in the office.
• Bypassing Geo-restrictions: Users can use VPNs to access content that might be restricted based on geographical location. By connecting to a VPN server in a different location, users can appear as if they are accessing the internet from that location.
• Site-to-Site Connectivity: In a business or enterprise setting, VPNs can establish secure connections between different locations, creating a virtual network that connects geographically dispersed offices or data centers.

Video on VPN

 

Published by Active Learning, Dec 2023