Wired Ethernet
Wired Ethernet refers to a networking technology that uses physical cables (typically Ethernet cables such as Cat5, Cat6, or Cat7) to connect devices like computers, printers, and switches within a Local Area Network (LAN).
- It relies on standards like IEEE 802.3 to ensure high-speed, stable, and reliable communication.
Key Characteristics:
- High data transmission speeds (up to 10 Gbps or more).
- Stable and reliable connections unaffected by interference.
- Requires physical cabling and associated hardware like switches.
- Limited mobility due to the fixed nature of cables.
Topology
Topology in Wired Ethernet refers to the arrangement of devices and cables in a network.
Common topologies include:
- Bus Topology: All devices are connected to a single backbone cable.
- Star Topology: Devices are connected to a central hub or switch, enhancing reliability.
- Ring Topology: Devices are connected in a closed loop, with data traveling in one or both directions.
- Mesh Topology: Every device is interconnected, offering high fault tolerance but increasing complexity.
Media Access Control (MAC)
Media Access Control determines how devices access the shared communication medium in Ethernet. Wired Ethernet typically uses:
CSMA/CD (Carrier Sense Multiple Access with Collision Detection):
- Devices listen to the network to detect if it’s free before transmitting.
- If a collision occurs, devices stop and retransmit after a random delay.
- This method was widely used in older Ethernet networks but has become less common with modern switches.
Types of Wired Ethernet:
- Standard Ethernet (10 Mbps)
- Fast Ethernet (100 Mbps)
- Gigabit Ethernet (1 Gbps)
- 10-Gigabit Ethernet (10 Gbps)
- Fiber Ethernet
Wireless Ethernet
Wireless Ethernet, commonly known as Wi-Fi, is a wireless networking technology based on IEEE 802.11 standards.
- It uses radio waves to transmit data, eliminating the need for physical cables, and allows devices to connect to a network within the range of a wireless access point.
Key Characteristics:
- Speeds depend on the Wi-Fi standard (e.g., Wi-Fi 5, Wi-Fi 6, or Wi-Fi 6E).
- Offers mobility and flexibility, allowing devices to connect from anywhere within range.
- Prone to interference from walls, other devices, and environmental factors.
- Requires encryption (e.g., WPA3) for secure communication.
Topology in Wireless Ethernet
Wireless Ethernet supports various network topologies, where devices communicate over a wireless medium, typically using access points (APs).
- The most common wireless topology is the Star Topology, where wireless devices (clients) connect to a central access point.
Common Topologies in Wireless Ethernet:
- Ad-hoc (Peer-to-Peer) Network: Devices communicate directly without a central access point.
- Infrastructure Mode (Star Topology): Devices connect to a central access point, which manages communication between devices and other networks.
- Mesh Network: Multiple access points work together to extend coverage and improve reliability.
Media Access Control (MAC) in Wireless Ethernet
Media Access Control in wireless Ethernet (Wi-Fi) governs how devices access the shared wireless medium. It ensures that only one device transmits at a time to avoid collisions.
Types of MAC Protocols:
- Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA): Used in wireless networks, this protocol listens for traffic before transmitting to avoid data collisions.
- RTS/CTS (Request to Send/Clear to Send): A mechanism to prevent collisions by sending a request before transmitting large data packets.
Wireless Ethernet Frame Layout
The wireless Ethernet frame layout is based on the Ethernet frame format but includes additional fields to handle the specifics of wireless communication.
Frame Structure:
- Frame Control: Identifies the type of frame (data, control, or management).
- Duration/ID: Specifies the duration the medium will be occupied.
- Address Fields: Includes Source Address (SA), Destination Address (DA), and sometimes Receiver Address (RA) and Transmitter Address (TA).
- Sequence Control: Used for keeping track of frames in a sequence.
- Data: The payload (actual data).
- FCS (Frame Check Sequence): Error-checking data to ensure the integrity of the frame.
Types of Wireless Ethernet (Wi-Fi)
- IEEE 802.11a: Operates on 5 GHz.
- IEEE 802.11b: Operates on 2.4 GHz.
- IEEE 802.11n: Operates on both 2.4 GHz and 5 GHz.
- IEEE 802.11ac (Wi-Fi 5): Operates on 5 GHz.
- IEEE 802.11ax (Wi-Fi 6): Operates on both 2.4 GHz and 5 GHz (also includes 6 GHz with Wi-Fi 6E).
Security in Wireless Ethernet
Security is a critical aspect of wireless Ethernet networks, as the wireless medium is more susceptible to interference and unauthorized access.
Wi-Fi Security Protocols:
- WEP (Wired Equivalent Privacy): An older and less secure protocol, now largely deprecated.
- WPA (Wi-Fi Protected Access): Improves upon WEP with better encryption (TKIP).
- WPA2: Uses stronger AES encryption, widely used for secure Wi-Fi networks.
- WPA3: The latest security protocol with improvements in encryption and protection against offline password attacks.
Common Security Measures:
- SSID (Service Set Identifier) Broadcasting: Disable SSID broadcast to hide the network name.
- MAC Address Filtering: Allows only specific devices to connect to the network based on their MAC address.
- Encryption: WPA2 or WPA3 encryption is essential to protect data transmitted over the wireless network.
- VPN (Virtual Private Network): Can be used to secure communications when accessing the network remotely.
