Obj 1.2 Network topologies and types Flashcards
Mesh
A mesh network is a type of network topology where each node is interconnected, allowing for multiple paths for data to travel between devices. In a mesh network, nodes can communicate directly with one another, and the network can continue to operate even if one or more nodes fail. There are two types of mesh topologies: full mesh, where every node is connected to every other node, and partial mesh, where only some nodes are interconnected.
For the exam, it’s important to recognize the advantages and disadvantages of mesh networks. The primary advantage is redundancy; if one path fails, data can be rerouted through another node, enhancing reliability and fault tolerance. This makes mesh networks suitable for applications requiring high availability, such as wireless networks in large buildings or disaster recovery systems. However, the complexity and cost of deploying a full mesh can be significant, as it requires more cabling or wireless links than simpler topologies. Understanding mesh networks and their implications for network design is crucial for your studies.
- Star/hub-and-spoke
The star topology, also known as hub-and-spoke, is a network design where all nodes are connected to a central hub or switch. In this arrangement, the central device acts as a point of communication, and all data travels through it before reaching its destination. Each node has a dedicated connection to the hub, which simplifies network management and troubleshooting.
For the exam, focus on the advantages and disadvantages of the star topology. One key advantage is its ease of installation and configuration; if one cable fails, it only affects the connected node and not the entire network. This topology also allows for easy addition or removal of devices without disrupting the network. However, the central hub represents a single point of failure; if it goes down, the entire network becomes inoperable. Understanding the implications of using a star topology is important for assessing network reliability and performance.
Bus
A bus topology is a network configuration where all devices are connected to a single central cable, known as the bus or backbone. Data is transmitted in both directions along the bus, and each device listens for messages addressed to it. When a device wants to send data, it broadcasts the message onto the bus, and all devices receive it, but only the intended recipient processes the data.
For the exam, it’s essential to know the advantages and disadvantages of bus topology. One advantage is its simplicity and cost-effectiveness, as it requires less cabling than star or mesh topologies. This makes it easy to set up and expand. However, bus topology has significant drawbacks; if the central cable fails, the entire network goes down. Additionally, as more devices are added, network performance can degrade due to increased collisions and traffic on the bus. Understanding bus topology is crucial for evaluating its suitability for various networking scenarios.
Ring
A ring topology is a network configuration where each device is connected to two other devices, forming a circular pathway for data transmission. In this setup, data travels in one direction around the ring, passing through each device until it reaches its destination. Each device has a repeater function to help propagate the signal, ensuring that data continues to flow around the ring.
For the exam, it’s important to recognize the advantages and disadvantages of ring topology. One key advantage is that data packets can travel quickly around the ring without collisions, as each packet has a designated path. This can lead to predictable and stable network performance. However, a major drawback is that if one device or connection fails, it can disrupt the entire network, unless a dual-ring topology is implemented for redundancy. Additionally, troubleshooting and adding devices can be more complex compared to star or bus topologies. Understanding ring topology is essential for evaluating its effectiveness in different networking environments.
Hybrid
A hybrid topology is a combination of two or more different network topologies, such as star, bus, ring, or mesh, tailored to meet specific networking requirements. This flexible design allows network architects to leverage the strengths of various topologies while minimizing their weaknesses. For instance, a common hybrid topology is a star-bus configuration, where individual star networks are connected to a central bus.
For the exam, focus on the benefits and challenges associated with hybrid topologies. One advantage is scalability; hybrid networks can easily accommodate growth by integrating new topologies as needed. They can also enhance reliability by isolating faults within specific segments, allowing parts of the network to function independently even if other sections fail. However, hybrid topologies can be more complex to design and manage, requiring careful planning to ensure compatibility and efficient communication between different topology types. Understanding hybrid topology is crucial for assessing its application in various networking scenarios and for optimizing network performance and reliability.
Peer-to-peer
Peer-to-peer (P2P) networking is a decentralized network model where all devices, or “peers,” have equal roles and responsibilities. Unlike traditional client-server models, where a central server provides resources or services, in a peer-to-peer network, each device can act as both a client and a server. Peers can share files, data, or resources directly with each other without needing a central authority.
For the exam, it’s important to know that peer-to-peer networks are often used for file sharing (such as in BitTorrent), decentralized applications, or small networks where simplicity is prioritized. One advantage is that P2P networks are highly scalable and resilient because there’s no central point of failure. However, they can be harder to secure and manage, and performance can degrade as the network grows, especially when peers are unreliable or have varying capabilities. Understanding P2P networking helps with evaluating decentralized network structures and their uses.
- Client-server
The client-server model is a network architecture where devices, known as clients, request services or resources from a centralized server. The server provides these services, such as file storage, web hosting, or database access, while managing and controlling the resources. The server typically runs continuously to handle multiple client requests, and the clients initiate connections when they need access to services.
For the exam, focus on the structure and benefits of this model. The client-server model is efficient for managing large networks, as the central server can handle security, resource allocation, and data management. This centralized control improves security and makes updates easier to implement. However, a key drawback is that if the server fails, clients are unable to access the services, creating a single point of failure. Understanding the client-server model is essential for evaluating how centralized systems function and the types of networks that benefit from this architecture.
Local area network (LAN)
A Local Area Network (LAN) is a network that connects devices within a limited geographic area, such as a home, office, or school. LANs are typically used to share resources like files, printers, or internet connections among multiple devices, such as computers, servers, and printers. LANs can be wired (using Ethernet) or wireless (using Wi-Fi).
For the exam, it’s important to understand that LANs offer high-speed data transfer and are cost-effective for connecting devices in close proximity. They are usually managed by switches, and data is often routed through a central router for external communications. LANs are often used to create private networks that can operate independently of the broader internet. Their small size and low latency make them ideal for small to medium-sized environments. Knowing the characteristics and components of LANs is crucial for understanding basic networking infrastructure.
- Metropolitan area network (MAN)
A Metropolitan Area Network (MAN) is a network that spans a larger geographic area than a Local Area Network (LAN), typically covering an entire city or a large campus. It connects multiple LANs within a metropolitan region to enable communication and resource sharing across distances that are too large for a single LAN but smaller than a Wide Area Network (WAN).
For the exam, understand that MANs are often used by businesses, government organizations, or universities to connect different buildings or sites within a city. They usually rely on high-speed fiber-optic connections and are managed by service providers or large organizations. A key point is that MANs provide efficient data communication over long distances with relatively high speeds compared to WANs. They play a crucial role in extending network connectivity and services across a broader geographic area while maintaining high performance. Understanding MANs helps in distinguishing between different scales of network infrastructures.
- Wide area network (WAN)
A Wide Area Network (WAN) is a type of network that spans large geographic areas, such as cities, countries, or even continents. WANs connect multiple smaller networks, like Local Area Networks (LANs) or Metropolitan Area Networks (MANs), enabling communication and resource sharing across great distances. The internet is the largest example of a WAN.
For the exam, it’s important to know that WANs typically use routers to direct traffic between locations, and they often rely on external services, like leased lines, satellite links, or fiber-optic cables, provided by telecommunications companies. WANs are crucial for connecting geographically dispersed offices or networks, but they generally have slower speeds and higher latency than LANs due to the long distances involved. WANs are used by large organizations to link multiple locations, and understanding how WANs operate, including their protocols and infrastructure, is essential for managing extensive network systems.
- Wireless local area network (WLAN)
A Wireless Local Area Network (WLAN) is a type of LAN that uses wireless communication technologies, typically Wi-Fi, to connect devices within a limited area like a home, office, or school. Instead of using physical cables, WLANs allow devices such as smartphones, laptops, and tablets to connect to the network and access shared resources wirelessly.
For the exam, focus on the characteristics of WLANs, such as the use of wireless access points (APs) to provide connectivity, and how they operate within specific frequency bands, usually 2.4 GHz or 5 GHz. WLANs are flexible, easy to install, and convenient for mobile devices, but they are more susceptible to interference, security risks, and have a shorter range compared to wired LANs. Understanding how WLANs are structured, their protocols (like IEEE 802.11), and security considerations (like WPA2 or WPA3) is crucial for grasping wireless networking concepts.
- Personal area network (PAN)
A Personal Area Network (PAN) is a small network designed for connecting devices within a very short range, typically within a few meters. PANs are used to connect personal devices like smartphones, tablets, laptops, and wearable devices for data exchange or communication. Technologies commonly used in PANs include Bluetooth, Infrared, and sometimes USB connections.
For the exam, it’s important to understand that PANs are designed for individual use and typically cover a range of about 10 meters. Bluetooth is the most common technology for PANs, allowing wireless communication between devices like headphones, printers, and smartphones. PANs are low-cost, easy to set up, and require minimal infrastructure, but they have limited range and data transfer speeds compared to larger network types. Knowing the applications and limitations of PANs is key to understanding the role of small-scale, personal networking in everyday use.
- Campus area network (CAN)
A Campus Area Network (CAN) is a network that connects multiple Local Area Networks (LANs) within a specific geographic area, such as a university campus, business campus, or a large corporate office park. It allows for efficient communication and resource sharing across buildings or departments that are in close proximity, typically within a few kilometers.
For the exam, focus on the fact that a CAN is larger than a LAN but smaller than a Metropolitan Area Network (MAN). CANs are often implemented using high-speed Ethernet or fiber-optic cables to provide fast and reliable connections between different parts of the campus. The network is usually managed by a single organization and is optimized for local use, providing high performance and centralized management. Understanding CANs helps in recognizing their role in large, local environments where multiple buildings need to stay connected.
- Storage area network (SAN)
A Storage Area Network (SAN) is a specialized, high-speed network that connects servers to a centralized pool of storage devices, such as disk arrays and tape libraries. SANs are designed to improve data storage and retrieval performance, providing dedicated access to storage resources for servers in a network.
For the exam, it’s important to understand that SANs are used in environments where fast, reliable access to large amounts of data is critical, such as in data centers or enterprise networks. SANs operate independently of the regular network traffic, ensuring that data storage tasks do not interfere with regular network operations. They often use technologies like Fibre Channel or iSCSI to provide high-speed data transfers. SANs enhance storage management, scalability, and data backup but can be complex and expensive to implement. Understanding SANs is crucial for learning about enterprise-level data storage solutions.
Software-defined wide area network (SDWAN)
A Software-Defined Wide Area Network (SD-WAN) is a technology that uses software to manage and optimize the routing of data traffic across a wide area network (WAN). Unlike traditional WANs, which rely on dedicated hardware and fixed routes, SD-WAN dynamically chooses the most efficient path for data based on real-time conditions such as bandwidth, latency, or network congestion. This flexibility improves performance, reduces costs, and simplifies network management.
For the exam, it’s important to understand that SD-WAN provides better control over WAN traffic by using software intelligence to prioritize critical applications and allocate bandwidth efficiently. SD-WAN also allows for integration with multiple types of connections, including broadband, MPLS, and LTE, improving overall network performance and redundancy. Key benefits include enhanced security, centralized control, and cost efficiency, making SD-WAN an attractive option for businesses with multiple branch offices or cloud services. Understanding how SD-WAN differs from traditional WANs is crucial for grasping modern WAN management trends.
