HUB, SWITCH, ROUTER

HUB, SWITCHES and ROUTERS

  • These are all used for connecting devices and networks together.
  • They all have ports for wires that do the physical connection.
  • Their intelligence level vary.

HUB

  • Function: Broadcasts data to all devices in a network.
  • OSI Layer: Layer 1 (Physical Layer)
  • How it works: When it receives data from one device, it sends that data to all other connected devices, regardless of the destination.
  • Drawbacks:
    • No filtering or intelligence.
    • Causes network congestion.
    • Security risk (any device can “hear” the data).
  • Use today: Rare — mostly replaced by switches.

Switch

  • Function: Forwards data to the specific device it’s intended for.
  • OSI Layer: Layer 2 (Data Link Layer) — some operate at Layer 3.
  • How it works: Maintains a MAC address table to identify which device is on which port. Sends data only to the correct port.
  • Advantages:
    • Reduces congestion.
    • More secure and efficient than hubs.
  • Use today: Common in both small and large networks.

Router

  • Function: Connects different networks together (e.g., home network to the internet).
  • OSI Layer: Layer 3 (Network Layer)
  • How it works: Uses IP addresses to route packets between networks. Can assign IP addresses (via DHCP), perform NAT, and filter traffic.
  • Advantages:
    • Allows internet access.
    • Manages traffic between networks.
    • Offers firewall and security features.
  • Use today: Essential for any network connected to the internet.

SWITCH Vs ROUTERS

  • A Switch transmit data among devices on a local network while a Router routes data among networks.
  • Switches use MAC addresses while Routers use IP addresses
  • Routers are far more powerful and provide additional features such as firewall protection.

ETHERNET

Ethernet

  • A protocol that determines how data is transmitted in a Local Area Network (LAN)
  • Technically referred to as IEEE 802.3 Protocol of wired networking.
  • Used to connect computers, routers, switches, and other devices within a physical space like a home, office, or data centre.
  • Most laptops & PC come with integrated ethernet cards
  • Known for being fast, reliable, and secure compared to wireless alternatives like Wi-Fi.

Ethernet Network Requirement

  • Computers and devices e.g. printer
  • Ethernet cards and ports e.g. RJ 45
  • Hubs or Switches
  • Cables
  • Software to manage the network

How Ethernet Connects Devices:

  1. Cabling:
    • Devices are connected using Ethernet cables (usually with RJ45 connectors).
    • Each device must have a Network Interface Card (NIC) with an Ethernet port.
  2. Networking Equipment:
    • Ethernet cables plug into devices like switches or routers, which manage data traffic.
    • A switch connects multiple devices in a LAN and forwards data only to the device it’s intended for.
    • A router connects the LAN to external networks like the internet.
  3. Data Transmission:
    • Data is transmitted in packets.
    • Each device has a MAC address, a unique identifier used to ensure data gets to the right destination.
  4. Speeds and Standards:
    • Speeds range from 10 Mbps (Ethernet) to 10 Gbps (10-Gigabit Ethernet) or more.
    • Backward-compatible standards allow older and newer devices to work together (at the lower speed).

 

Ethernet Process with Example

  • Device A wants to send data to Device B
  • Device A checks to see if the carrier (main wire connecting the devices) is free
  • If YES, device A sends the data packet on the network
  • Device B receives the packet
  • If NO, device A waits for some thousandths of second and then tries again.

Home Network:

  • Your PC, smart TV, and printer connect via Ethernet cables to a router or switch.
  • The router then connects to the modem, which provides access to the internet.