Local Area Network (LAN) and its Types

Definition

• A Local Area Network (LAN) is a computer network that connects devices within a limited area, such as a home, office, or campus.

• LANs are designed to facilitate communication and resource sharing between connected devices

  Types of LAN TOPOLOGIES

  Bus Topology:

  • All devices are connected to a single_ended cable, forming a linear network.

  • Advantages: Easy to install and cost-effective as it requires less cabling. Suitable for small networks.

  • Disadvantages: If the main cable fails, the entire network goes down. Limited scalability and potential for collisions.

  Star Topology:

  • All devices are connected to a central hub or switch.

  • Advantages: Easy to add or remove devices without affecting the network. Fault isolation as a single device failure doesn't impact the entire network.

  • Disadvantages: Dependent on the central hub, if it fails, the entire network is affected. Requires more cabling compared to bus topology.

  Ring Topology:

  • Devices are connected in a circular manner, forming a closed loop.

  • Advantages: Equal access to network resources, as each device has the same opportunity to transmit data. No collisions.

  • Disadvantages: Failure of a single device or cable can disrupt the entire network. Difficult to add or remove devices without disrupting the network.

  Switched Topology:

  • Devices are connected to a central switch, which manages data flow.

  • Advantages: Efficient data transmission as the switch directs data only to the intended recipient. No collisions. Scalable and flexible.

  • Disadvantages: costs more due to the need for switches. Failure of the central switch affects the entire network.

  Daisy Chain Topology:

  • Devices are connected in a linear manner, one after another

  • Advantages: Simple and easy to implement. Suitable for small networks with few devices.

  • Disadvantages: If any device or cable fails, the entire network is affected. Limited scalability and potential for collisions.

  Hierarchy Topology:

  • Combination of different topologies, typically a mix of star and bus or star and ring.

  • consist more than one layer of hubs

  • the bottom tier is reserved for user station

  • Hierarchical Star:

    • The hierarchical star topology is a network configuration where multiple star networks are interconnected through a central hub or switch.

    • In this topology, each star network has its own central node, which connects to the central hub or switch.

    • The central hub or switch acts as a bridge, allowing communication between the different star networks.

    • This topology is commonly used in large networks where multiple smaller networks need to be connected and managed efficiently.

    • It provides scalability and flexibility as new star networks can be easily added or removed without affecting the entire network.

    • However, the hierarchical star topology can be more complex to set up and maintain compared to other topologies.

    Hierarchical Ring:

    • The hierarchical ring topology is a network configuration where multiple ring networks are interconnected in a hierarchical manner.

    • In this topology, each ring network has its own set of nodes, and one or more nodes from each ring are connected to form a higher-level ring.

    • The higher-level rings are then connected to form an even higher-level ring, creating a hierarchical structure.

    • This topology allows for efficient communication within each ring network and between different levels of the hierarchy.

    • It provides fault tolerance as a failure in one ring network does not affect the entire network.

    • However, the hierarchical ring topology can be more complex to manage and troubleshoot compared to other topologies.

    Hierarchical Combination:

    • The hierarchical combination topology is a network configuration that combines elements of both the hierarchical star and hierarchical ring topologies.

    • It is designed to provide the benefits of both topologies, such as scalability, fault tolerance, and efficient communication.

    • In this topology, multiple hierarchical star networks are interconnected in a hierarchical manner, similar to the hierarchical ring topology.

    • Each hierarchical star network has its own central hub or switch, and one or more hubs or switches from each network are connected to form a higher-level network.

    • This hierarchical structure allows for easy expansion and management of the network while providing fault tolerance and efficient communication.

    • The hierarchical combination topology is commonly used in large enterprise networks where scalability and reliability are crucial.

  • Advantages: Provides flexibility and scalability. Suitable for larger networks with multiple subnetworks.

  • Disadvantages: Complex to design and implement. Requires more cabling and additional hardware.

  Note: Each topology has its own advantages and disadvantages, and the choice depends on factors such as network size, cost, scalability, and fault tolerance.

  Wide Area Networks (WAN) and their Topologies

  Wide Area Networks (WAN)

  • WAN is a type of computer network that spans a large geographical area, connecting multiple local area networks (LANs) or other WANs.

  • It allows organizations to connect their remote offices, branches, or sites over long distances.

  • WANs utilize various technologies such as leased lines, satellites, and public networks to establish connectivity

    Peer-to-Peer Topology

    • Also known as a decentralized network.

    • Each node in the network can act as both a client and a server.

    • Nodes communicate directly with each other without a central server.

    • Offers high scalability and fault tolerance.

    • Examples include file-sharing networks like BitTorrent.

    Ring WAN Topology

    • Nodes are connected in a circular manner, forming a ring.

    • Each node is connected to exactly two other nodes.

    • Data flows in a unidirectional manner around the ring.

    • Offers simplicity and equal access to all nodes.

    • Failure of a single node can disrupt the entire network.

    Star Topology

    • Consists of a central node (hub or switch) connected to multiple peripheral nodes.

    • All communication passes through the central node.

    • Offers easy management and fault isolation.

    • Failure of the central node can bring down the entire network.

    • Commonly used in home networks and small businesses.

    Full-Mesh Topology

    • Each node is directly connected to every other node in the network.

    • Offers high redundancy and fault tolerance.

    • Provides multiple paths for data transmission.

    • Requires a large number of physical connections, making it expensive and complex to implement.

    • Commonly used in critical applications where high reliability is essential.

    Partial Mesh Topology

    • Only a subset of nodes are directly connected to each other.

    • Offers a balance between cost and redundancy.

    • Provides some level of fault tolerance and scalability.

    • Requires careful planning to determine which nodes should be directly connected.

    • Commonly used in medium-sized networks.

    Two-Tiered Topology

    • Consists of two layers: access layer and distribution layer.

    • Access layer connects end-user devices to the network.

    • Distribution layer connects access layer switches to the core network.

    • Offers scalability, flexibility, and centralized management.

    • Suitable for medium to large-sized networks like corporate environments.

    The three-tiered WAN topology

  • is a network architecture with three layers: access, distribution, and core. The access layer connects end-user devices and handles local traffic. The distribution layer acts as a middleman and connects access layer switches to the core layer. The core layer is the backbone of the network and ensures fast communication between distribution layer switches. This topology offers scalability, improved performance, and network reliability. It is commonly used in large organizations or campuses. However, implementing it requires careful planning and understanding of network design principles. Overall, it provides a structured and efficient network for organizations needing a scalable, reliable, and high-performance WAN infrastructure.

    Hybrid WAN Topology

    • Combines multiple topologies to meet specific requirements.

    • Allows organizations to leverage the benefits of different topologies.

    • For example, a hybrid WAN may use a star topology for local branches and a partial mesh for interconnecting remote branches.

    • Offers flexibility, scalability, and cost-effectiveness.

    • Requires careful planning and design to ensure seamless integration.

    .

  Advantages of WAN

  • Geographical Flexibility: Allows organizations to connect remote sites across different locations.

  • Resource Sharing: Enables sharing of resources like servers, databases, and applications.

  • Centralized Management: Provides centralized control and management of network resources.

  • Scalability: Can easily accommodate the addition of new sites or users.

  Disadvantages of WAN

  • Cost: Implementing and maintaining WAN infrastructure can be expensive.

  • Complexity: Setting up and managing WANs can be complex, requiring specialized knowledge.

  • Reliability: Dependence on external networks and service providers can lead to potential downtime.

  • Security: WANs are more vulnerable to security threats compared to LANs.

  Note: WAN topologies and their advantages/disadvantages may vary depending on specific implementations and technologies used.

QUESTIONS
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