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Network Topology

Topology refers to the structure of a network and can be divided into two types: physical and logical. Physical network topology refers to the actual architecture of a network, and networks using one physical topology will interconnect components differently than those using another. The two main types of physical network topologies are star and bus.

In a physical star network, each client has a direct connection to a central hub, which is responsible for receiving packets from all clients and delivering them to the correct recipient. The advantages of this setup include direct packet delivery, ease of adding and removing clients, and minimal impact on the performance of the network if one cable fails. However, if the central hub fails, all communication stops, and installation can be expensive due to the amount of cable required.

On the other hand, a physical bus topology connects clients to a single cable known as the backbone, with a terminator at each end. This design eliminates the need for a central hub, reducing network failure risks and installation costs. However, all clients can see packets not intended for them, and if the backbone fails, the entire network becomes unusable.

Logical network topology is distinct from physical topology; it refers to the flow of data packets within a network. For instance, a logical bus network delivers packets to all clients, while a logical star network delivers packets only to their intended recipient. It is also possible for a network set up as a physical star to behave as a logical bus, indicating flexibility in network design.

Moving on to types of networking between hosts, hosts are devices on a network that provide services, commonly servers offering file storage, printer sharing, and internet access. In a client-server network, one or more central servers provide services to clients, allowing for central management, enhanced security, but requiring substantial expertise to operate. Conversely, peer-to-peer networking eliminates a shared server, enabling clients to provide equal service status. While this approach reduces costs and simplifies setup, it poses risks as the network depends on all clients being operational.

Wireless networking enables communication without physical connections, requiring a wireless access point and a device’s wireless network adapter. WiFi, based on international standards, allows devices to connect globally and relies on security measures like WPA or WPA2 encryption, SSID broadcast disabling, and MAC address filtering.

To manage data collisions, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) is utilized in wireless networks, where devices listen to the communication channel before transmitting data. If the channel is busy, devices wait a randomized period before rechecking. This model, while effective in small networks, cannot fully resolve issues like hidden nodes, for which the Request to Send/Clear to Send (RTS/CTS) protocol is employed to enhance communication efficiency when detecting idle channels.