REAL COMPUTER NETWORK ENVIRONMENT
Introduction
Data communication in a real computer network environment refers to the process of transmitting and receiving data among devices in a network. There are several functions for data communication in a computer network environment. First, data representation Data is represented in binary form using bits (0s and 1s) in computer networks. Information such as text, numbers, images, and multimedia is encoded into binary format before transmission. Second, sender and receiver In data communication, there is a sender (source) and a receiver (destination) involved. The sender is the device or application that initiates the transmission, while the receiver is the device or application that receives the data. Third, transmission medium: The term "transmission medium" refers to the physical pathway through which data is transmitted between devices in a network. It can be wired (e.g., Ethernet cables, fiber optic cables) or wireless (e.g., radio waves, Wi-Fi). Fourth, Protocols: Protocols define the rules and procedures for data communication. They govern how data is formatted, transmitted, received, and interpreted. Common network protocols include TCP/IP (Transmission Control Protocol/Internet Protocol), Ethernet, Wi-Fi, HTTP (Hypertext Transfer Protocol), and DNS (Domain Name System). Next, packetization: To transmit data efficiently, it is divided into smaller units called packets. Each packet contains a portion of the data, along with headers that provide addressing and control information. Packetization allows for more efficient and reliable transmission across the network. After that, address and routing: Devices in a network are identified by unique addresses. IP addresses are used in the TCP/IP protocol suite to uniquely identify devices on the Internet. Routing protocols determine the optimal path for data packets to reach their destination across interconnected networks. Error Detection and Correction: Data communication includes mechanisms for error detection and correction to ensure data integrity. Checksums or error-detection codes are often added to packets to detect errors during transmission. Forward error correction techniques can be used to correct errors at the receiver's end. Furthermore, network devices: Various network devices facilitate data communication in a network environment. These include routers, switches, hubs, modems, and wireless access points. They help in forwarding, filtering, and managing the flow of data across the network. Finally, security and encryption: in a real computer network environment, data communication often involves security measures to protect sensitive information. Encryption protocols, firewalls, and virtual private networks (VPNs) are employed to secure data transmission and prevent unauthorized access.
Wireshark
To do this project, our team used Wireshark. The popular open-source network protocol analyzer Wireshark enables users to record, examine, and debug network traffic. It offers a wide range of features and capabilities that support network analysis and security. These are some of the main functions of Wireshark. First, network traffic capture: Wireshark captures network traffic on a specified network interface or from a saved capture file. It can capture packets from wired and wireless networks and supports a variety of network protocols. Second, protocol analysis: Wireshark decodes and analyses network protocols at various layers of the network stack. It provides detailed information about packet headers, payloads, and other protocol-specific details. This helps in understanding how different protocols are being used and identifying any issues or anomalies. Third, packet filtering and search: Wireshark allows users to apply filters to capture and display specific packets based on criteria such as source or destination IP address, port number, protocol type, or specific patterns in packet contents. This helps in isolating and analysing relevant packets from large capture files. There are four protocols used in the Web Interaction Model: TCP (Transmission Control Protocol), IP (Internet Protocol), HTTP (Hypertext Transfer Protocol), and FTP (File Transfer Protocol). The network transmits data between and among computers, allowing them to communicate. Data is transmitted via cables (dedicated connections) or phone lines (dial-up connections) and enters the computer via an adapter called a NIC (Network Interface Card) or a modem. Data transmissions follow established protocols. The Internet uses a protocol named IP (Internet Protocol) that distributes traffic from one network to another using a number of public routers and servers. IP works in conjunction with a protocol called TCP (Transmission Control Protocol), which ensures reliable end-to-end delivery of messages. By doing this, we can get the main outcome of this project, which is to construct a dashboard tool to monitor network traffic activities.
A network protocol that we use:
Step by step using Wireshark:
Capturing Packets Using Wireshark
1. Download the Wireshark program and open it. You will be greeted with something like the screen below.
2. Choose Wi-FI by double clicking it and Wireshark will automatically start capturing the packets from your Wi-Fi.
3. Now, to view the captured packets in graph, go to the Statistics drop down menu and click on I/O Graphs.
4. After clicking on the I/O Graphs option, a new window will be opened by Wireshark. The window should look something like this.
5. Now, let’s say that we want to view the captured packets of TCP, HTTP, and FTP in the graph. To do so, just change the Display Filter at the bottom of the window for each of the graphs. Change it to tcp, http, and ftp respectively. When changing the Display Filter, the suggestion will appear as you type. When the suggestions appear, just click on the one that you want to choose. When the correct display filter is entered, the background will turn green. It should look something like this.
6. Continue the same thing for http and ftp. You can add more graphs by clicking the “+” icon at the bottom of the window. In the picture below, we also added ftp-data Display Filter to see the graph when someone is copying some files from the FTP server. Additionally, the color, name and style of each graph has also been changed. The completed I/O Graphs should look something like this.
7. Now let’s say that your HTTP graph is not capturing any packets. Try to play some videos on YouTube and check your Wireshark window to see the captured packets. In our case, the captured packets are in QUIC protocol instead of HTTP. This is because our Wi-Fi is using Google DNS Server which is 8.8.8.8.
Addtionally, you can check which DNS Server that your Wi-Fi is using by going to Command Prompt and type ipconfig /all. The output should look something like this.
8. Now your graph is ready to monitor the network traffic. The picture below is the completed I/O Graphs for my Wi-Fi network.
Cash Team member's biography:
Hello, My name is Syed Nor Irfan Bin Syed Ahmad Syakirin. I'm currently taking Database Management Bachelor's Degree at Universiti Teknikal Malaysia Melaka (UTeM). Since young, I am always interested in things that related to computer.
