network revisioin.docx

Explain the difference between logical and physical network topologies. - Physical topology -shows you actual connectivity and the layout of a network and cable connections, where the router is, LAN etc. - Logical topology -- shows virtual view of the layout and/or connectivity that de...

Explain the difference between logical and physical network topologies. - Physical topology -shows you actual connectivity and the layout of a network and cable connections, where the router is, LAN etc. - Logical topology -- shows virtual view of the layout and/or connectivity that devices in a network see, how data flows from one device to another.\  \  \ 2.       **Describe how each of the following physical network topologies transmits data and specify appropriate cabling and connectors for each.**\ ·         Bus- devices connected through shared cabling (bus), with taps and drop lines. All connected devices use same cable data frame transmission. (all devices receive frame but only device with destination MAC address accepts received frame).\ ·         Star- devices connect to central device (switch/hub) with a point-to-point link (dedicated link or cable) between devices. (data frames first routed through central device and broadcast or unicast the received frame to destination device)\ ·         Ring- Each device is connecting to two adjacent devices to form a ring. (data is transmitted from one device to another in a circular motion).\ ·         Mesh- Each device has point to point link to every device in network, using simplex or duplex links. (simplex- data moves in one direction only, one link for sending data and other for receiving data from adjacent device) (Duplex- data can move in both directions, can replace two simplex links with one duplex)\ ·         Hybrid or Tree- topologies interconnected. 1. **Describe data communication systems hardware and software components that are typically used in constructing and configuring a LAN.** Include in your description a minimum of **seven** hardware and **four** software components. 1. **Identify two wiring standards and explain the difference between them.** - The two common wiring standards for Ethernet cables in LANs are **TIA/EIA-568A** and **TIA/EIA-568B**, they define the colour-coding sequence of the wires within an ethernet cable. The main difference between TIA/EIA-568A and TIA/EIA-568B is the color-coding of the wires. - Using one standard simplifies network installation and maintenance.  **Hardware Components:** 1. **Router**: - Connects the LAN to the internet and routes data between devices in the network and external networks. 2. **Switch**: - A central device that connects multiple devices (like computers, printers, etc.) within a LAN, allowing them to communicate with each other. - If different wiring standards are used on both ends of the cable it creates a crossover cable which enables you to connect devices without a switch. 3. **Modem**: - Connects the LAN to the internet service provider (ISP) by converting digital signals to analogue for transmission over phone lines or cable systems. 4. **Network Interface Card (NIC)**: - A hardware component inside computers or devices that allows them to connect to the LAN, typically via an Ethernet cable or Wi-Fi. 5. **Cabling (Ethernet Cables)**: - Physical cables that connect devices to the switch or router for wired communication. - The two wiring standards, TIA/EIA-568A and TIA/EIA-568B perform the same function. The only difference is the colour coding of wires, which does not affect data transmission if the same standard is used on both ends of the cable. 6. **Access Point (AP)**: - A device that provides wireless connectivity to the LAN, allowing devices like laptops and smartphones to connect to the network through Wi-Fi. 7. **Servers**: - Computers that provide services to other devices on the network, such as file storage, web hosting, or network management. **Software Components:** 1. **Operating System (OS)**: - Software on devices that manages network connections, such as Windows, macOS, or Linux. 2. **Network Management Software**: - Tools that help configure, monitor, and manage the network, such as configuring IP addresses, monitoring traffic, and setting security policies. 3. **Firewall Software**: - Protects the network by controlling incoming and outgoing traffic based on security rules, preventing unauthorized access. 4. **Antivirus/Anti-Malware Software**: - Protects devices on the LAN from malicious software, ensuring data and network security. ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** **\ ** ** 1. **Identify three wireless standards.**        **Wi-Fi (IEEE 802.11)**: Used for wireless networking, allowing devices like laptops and smartphones to connect to a network or the internet without cables. - **Bluetooth (IEEE 802.15.1)**: Used for short-range communication between devices, such as connecting wireless headphones to a smartphone. - **NFC (Near Field Communication)**: Used for very short-range communication, typically for contactless payments or data exchange between devices by simply bringing them close together.  \  \  \  \  \  \  \  \  \  \ 3.       **Describe the function of each layer of the OSI model and explain how the layers relate to each other, including encapsulation and framing.** 1. **Physical layer** -- lowest layer, responsible for carrying raw data bits across physical hardware. E.g. ethernet cables. Encapsulated frames are transmitted over the network in bits, when the web server receives the bits from the network it reverses the process. 2. **Data link layer**- takes bits of data from the physical layer and organises them into frames, ensures frames are delivered to the correct destination. Source and destination MAC addresses and switch located on this layer and the Ethernet protocol. 3. **Network layer**- responsible for IP addressing and routing. Source and destination IP address added on this layer and routers operate on this layer. Routes data frames across layers, frames are encapsulated with IP protocol and ICMP protocol. 4. **Transport layer**- Adds transport protocols like UDP and TCP (error handling and sequencing to avoid data loss). Delivers data and manages the delivery processes, sequence, reliability, and provides source and destination port numbers. This encapsulates into TCP segments at this layer. 5. **Session layer**-Establishing and terminating connections between devices. Ensures the session is open whilst data is coming through. 6. **Presentation layer**- Formats data the way the receiving application can understand it. Converts data into text, sound, video etc. can also decrypt and encrypt if necessary. 7. **Application layer**- responsible for app and user communication. Interaction with protocol that gets data to the user e.g. SMTP protocol when user wants to send an email. The HTTP, FTP and SMPT protocols are present at this layer.  \  \  \  \  \  \ ** ** 1. **For each layer of the OSI model, describe the key features, protocols and standards.**  \  \  \  \  \  \  \  \  \  \ 5.       **Describe the functions and key features of the four layers of the Internet Protocol (TCP/IP) model.\ ** \  The Transmission Control Protocol/Internet protocol allows you to understand how data is transmitted over the internet. It divides communication tasks in four layers. **Application layer** - This layer is where users interact with application data such as emails or web browser and programs that need TCP/IP to communicate with each other. - HTTP, SMTP and FTP protocols are found at this layer. It combines the session, presentation and application layer of the OSI model. **Transport Layer** - This layer is responsible for ensuring data is delivering reliable data between a device/application and its intended destination. Data is divided into packets and a sequence is created, and ensures the packets are delivered error free. - The UDP and TCP protocol is present at this layer and contains transport data, the source and destination port numbers, sequence etc. and faster reliable communication. **Internet layer** - This layer is responsible for routing packets of data from the source to its destination across networks. - This layer contains the IP protocol, which handles addressing and routing, provides the source and destination IP address. **Data link layer** - This layer provides the link between the physical network (e.g. ethernet), it deals with physical data transmission over hardware in the network. - It includes MAC protocols including destination and source MAC addresses with added error checking and once data hits the physical layer it is physically transmitted.  \  \  \  \  \  \  \  \ 6.       **Describe the protocols of each TCP/IP layer.**  **Application Layer:** - **HTTP (Hypertext Transfer Protocol)**: Used for browsing the web; it transfers web pages from servers to browsers. - **FTP (File Transfer Protocol)**: Used for transferring files between computers on a network. - **SMTP (Simple Mail Transfer Protocol)**: Used for sending emails from a client to a server or between servers. **Transport Layer:** - **TCP (Transmission Control Protocol)**: Ensures reliable, ordered, and error-checked delivery of data between applications. - **UDP (User Datagram Protocol)**: Provides a faster, method for sending data but doesn't guarantee delivery or order **Internet Layer:** - **IP (Internet Protocol)**: Responsible for addressing and routing packets of data so they can travel across networks and reach the correct destination. - **ICMP (Internet Control Message Protocol)**: Used for network diagnostics and error reporting. E.g. 'ping' command. - **ARP (Address Resolution Protocol)**: Translates IP addresses into MAC (hardware) addresses so that data can be sent to the correct physical device on a local network. **Data link layer:** - **Ethernet**: For wired networking, which defines how data is formatted and transmitted over physical cables. - **Wi-Fi**: A protocol for wireless networking, allowing devices to connect to a network without cables. 1. **Explain how the TCP/IP model relates to the OSI model.** - The Application Layer of the TCP/IP model combines the functions of the Application, Presentation, and Session Layers of the OSI model. - The Transport Layer of the TCP/IP model and the Transport Layer of the OSI model, both ensure reliable data delivery, with TCP providing similar functions in both. - The Internet Layer of the TCP/IP model and the Network Layer of the OSI model, both handle the same tasks of logical addressing and routing. - The Data Link layer of the TCP/IP model combines the responsibilities of the Data Link and Physical layers of the OSI model, dealing with the actual physical transmission of data over a network.