Lesson 1.1C: Hardware

• Repeater - operates at the physical layer and amplifies signals within a Local Area Network. It is a 2-port device that can extend the length to which the signal can be transmitted over the network.
• Hub - multiport repeater - broadcasts received data to connected devices in a local area network. It cannot filter data effectively, so the data packets are sent. - collision domains of hosts
• Switch - Data-link layer devices that intelligently direct data to specific recipients based on Media Access Control devices.

  • divides the collision domain of hosts, but the broadcast domain remains the same
• TYPES OF SWITCH:

  • Unmanaged
  • Managed
  • Smart
  • Data-Link Layer
  • Network Layer
  • Power over Ethernet
  • Gigabit
  • Rack-mounted
  • Desktop
  • Modular
• Bridge - operates at the data link layer. It is used to connect LAN segments with the same protocols.

  • interconnecting two LANs working
• TYPES OF BRIDGES:

  • Transparent Bridges - the stations are completely unaware of the bridge's existence
  • Source Routing Bridges - routing operations are working with the discovery frame to be sent from the host which spreads through the entire network using all possible paths to the destination.
• Router - Functions at Network Layer, connecting different LANs and making forwarding decisions based on IP addresses.

  • pivotal in managing data traffic between different networks - significantly impacting network performance and reliability.
• Multi-Layer Switch - capable of performing functions of both switches and routers, operating at both Data Link and Network Layers.

  • route packets on Application Specific Integrated Circuit (ASCI) hardware
• Seven Layers in OSI Model:

  Physical Layer

  Data Link Layer

  Network Layer

  Transport Layer

  Session Layer

  Presentation Layer

  Application Layer
• Brouter - combination of a bridge as well as a router. Data link or Network layer, capable of filtering LAN traffic.
• Modem - combination of modulator and demodulator

  Its ability to convert the signal is crucial for internet access, enabling users to connect to their IPs.

  • Digital Subscriber Line to cellular connections
• Modulator is the digital information that shall be carried on your analog carrier signal.

  Demodulator retraces the transmitted signal that is the transmitter digital information.
• Firewall (Security Device) - critical for network security, filtering incoming and outgoing traffic based on various criteria.

  • Protection for cyber threats, firewalls are designed as indispensable in safeguarding networks
  • maintain the integrity and confidentiality of data