Computer Networking Devices

Network Devices

• A Network Interface Card (NIC) enables a device to send and receive data over a network.
• A Repeater is a network device that receives a signal and retransmits it at a higher power level, extending the signal range.
• A Bridge connects two LAN segments and forwards packets between them, operating at the data link layer of the OSI model and using MAC addresses to forward packets.
• A Gateway connects two networks with different protocols, translating data between them so they can communicate with each other.
• A Load Balancer distributes network traffic across multiple servers, improving performance and availability by ensuring no single server becomes overloaded.
• Network Attached Storage (NAS) is a type of storage device attached to a network, allowing multiple devices to access and share files.
• A Content Filter examines network traffic, blocking or allowing access to specific types of content.

Computer Networks

• A computer network facilitates communication and data transfer between devices, applications, and users.
• Network types include:
  • Local Area Network (LAN)
  • Wide Area Network (WAN)
  • Metropolitan Area Network (MAN)
  • Personal Area Network (PAN)
  • Storage Area Network (SAN)
  • Campus Area Network (CAN)
  • Virtual Private Network (VPN)

Network Topologies

• Bus Topology:
  • Advantages: easy to set up and maintain, requires less cable, and suitable for small networks.
  • Disadvantages: not very secure, can be slow with many devices, and difficult to identify and fix problems.
  • Applications: small networks with limited devices, non-critical applications, and cost-effective solutions.

Network Fundamentals

• Understanding network architectures, topologies, and protocols is essential for effective communication between network devices.
• The OSI model ensures standardized communication between devices from different manufacturers.

OSI Model

• The OSI model consists of seven layers:
  1. Physical Layer: defines physical network characteristics.
  2. Data Link Layer: provides reliable data transfer over a physical link.
  3. Network Layer: routes data between networks.
  4. Transport Layer: provides end-to-end data transfer between devices.
  5. Session Layer: establishes, manages, and terminates connections.
  6. Presentation Layer: converts data into a format that can be understood by the receiving device.
  7. Application Layer: provides services and interfaces for applications to communicate with each other.