Network Types, MAC Addresses, and OSI Model Explained

Network Classification by Device Roles

Networks can be classified based on the roles of the devices within them:

• Client-Server: This is the most common type. A powerful server provides services to multiple clients and is always available. Example: A web server.
• Peer-to-Peer: In this model, all computers have equal roles and share resources directly. Example: BitTorrent.

Router Functions in Home Networks

Routers provided by Internet Service Providers (ISPs) often integrate the functions of multiple devices, including:

• Hub
• Modem
• Access Point

MAC Address Translation

The MAC address 08-2E-5F-14-93-A0 in decimal is 8-46-95-20-147-160.

Switches and the OSI Model

Switches operate at Level 2 (Data Link Layer) of the OSI model. Other devices that work at this level include:

• Bridges
• Network Interface Cards (NICs)

The data unit at the Data Link Layer is called a frame.

Understanding MAC Addresses

A MAC address is a unique identifier assigned to network interfaces. For example, in the MAC address 00-13-D4-08-E9-60:

• The first part (00-13) identifies the manufacturer.
• The second part (D4-08-E9-60) is the serial number of the network card.

This structure ensures that no two devices have the same MAC address.

Network Topologies

Networks can also be classified by their topology:

Star Network

In a star network, each device connects directly to a central switch or hub via its own cable. A hub broadcasts data to all devices, while a switch directs data only to the intended recipient.

Advantages:

• High reliability: If one cable or device fails, others remain unaffected.

Disadvantages:

• Higher installation cost due to extensive cabling.

Bus Network

In a bus network, all devices (workstations, servers, printers) share a single cable (the bus). Terminators at each end prevent signal reflection.

Advantages:

• Easy and inexpensive installation due to less cabling.

Disadvantages:

• Network failure if the main cable fails.

Ring Network

In a ring network, each device connects to two others, forming a closed loop. Data travels in one direction, passing through each device until it reaches its destination.

Advantages:

• Fast data transfer due to unidirectional flow, avoiding data collisions.

Disadvantages:

• Network failure if the main cable or any device fails.