Network_Overview of network devices

 

Network Interface Card (NIC):
A Network Interface Card (NIC) is a device that allows a computer to connect to a network.

NICs have a unique Media Access Control (MAC) address physically embedded in them,

which is used to identify each device within the network.

 

 

Hubs:
Hubs are older central connecting devices that act as multi-port repeaters.

They operate at the Physical Layer (Layer 1) of the OSI model and

transmit data to all connected devices.

For example, if System 1 sends data to System 2, Systems 3 and 4 will also receive that data.

This method increases the possibility of network collisions and

can lead to data transmission conflicts when multiple devices send data simultaneously.

Hubs have largely been replaced by switches.

 

 

Switches:
Switches are the primary central connecting devices in modern networks,

operating at the Data Link Layer (Layer 2) of the OSI model.

Switches remember the MAC addresses of connected devices and

only send data to the intended recipient, which helps prevent network collisions.

This improves both network efficiency and security.

 

 

Wireless Access Point (WAP):
A Wireless Access Point is a device that connects a wired network to a wireless network.

Operating at the Data Link Layer (Layer 2) of the OSI model,

WAPs function similarly to switches, except they handle wireless devices.

They transmit signals and manage connections for wireless devices to access the network.

 

 

Wireless Range Extender:
A Wireless Range Extender amplifies wireless signals to extend the network's range.

Acting as a wireless repeater,

it provides additional signal strength in areas that need enhanced network coverage.

 

 

Routers:
Routers are devices that transmit data between networks,

operating at the Network Layer (Layer 3) of the OSI model.

Routers use IP addresses to send data along the optimal path and connect different networks.

They also provide security features and traffic management to enhance

network efficiency and security.

 

 

Modems:
A modem is a device that converts analog signals to digital signals.

For example, it converts analog signals received from an Internet Service Provider

into digital signals for use by the user's system.

Modems also perform the reverse function, converting digital signals back into analog signals.

 

 

SOHO (Small Office Home Office) Devices:
SOHO devices are networking equipment designed for small spaces.

Although typically associated with routers,

these devices often integrate various functionalities such as wireless access points, firewalls,

and switches into a single device, making them useful for small network environments.

 

 

Media Converters:
Media converters are devices that connect different types of network media.

For example, they can support connections between

fiber optic cables and standard Ethernet cables.

Media converters operate at the Physical Layer (Layer 1) of the OSI model,

converting signal types to provide network compatibility.

 

 

Firewalls:
Firewalls are fundamental devices for network security,

available in both hardware and software forms.

Firewalls monitor and filter network traffic to prevent unauthorized

or harmful traffic from accessing the network.

 

There are three main types of firewalls:

- First-generation Firewalls:

   Packet-filtering firewalls that maintain security by applying basic filtering rules to data.

- Second-generation Firewalls:

   Circuit-level firewalls that monitor valid and invalid TCP sessions.

 

DHCP Server:
A DHCP (Dynamic Host Configuration Protocol) server is a server

that dynamically assigns IP addresses to network devices.

When a device connects to the network, the DHCP server automatically assigns an IP address,

automating the network configuration process.

The DHCP process consists of four stages: Discover, Offer, Request, and Acknowledge (DORA).

 

VoIP Endpoints:
VoIP (Voice over IP) endpoints are devices that enable voice communication over a network.

VoIP systems use IP addresses and MAC addresses to transmit voice data over the network,

and most modern telephone systems use VoIP technology.