Internet Connectivity | Lecture 11, 12 | M2

Dial-up connections through the telephone system were the primary method for accessing the internet in the early days of the World Wide Web. Dial-up connections use the Public Switched Telephone Network (PSTN) to connect to an Internet Service Provider (ISP). The connection is established through the use of a modem, which translates the digital signals used by the computer into analog signals that can be transmitted over the telephone line.

Dial-up connections are slow and are limited to a maximum speed of 56 kbps due to limitations in the telephone network. Additionally, dial-up connections can tie up the telephone line, making it unavailable for voice calls while the internet connection is in use.

Dedicated Connections through the Telephone System:

Dedicated connections through the telephone system are also known as leased lines. These connections provide a dedicated, always-on connection between two points, such as a business and an ISP. Dedicated connections use a separate physical circuit from the PSTN and are typically used for high-speed data transfer, such as video conferencing or large file transfers.

ISDN:

ISDN (Integrated Services Digital Network) is a set of communication standards for digital transmission of voice, video, and data over the PSTN. ISDN uses a digital signal instead of an analog signal, allowing for faster data transfer rates of up to 128 kbps. ISDN also allows for the use of multiple channels, providing additional bandwidth for data transfer.

Protocol Options:

There are several protocol options for connecting to the internet, including Shell, SLIP, and PPP.

Shell (Bourne-Again SHell) is a command-line interface that provides access to a Unix-based system. Shell is used primarily by developers and system administrators and is not typically used for connecting to the internet.

SLIP (Serial Line Internet Protocol) is an older protocol that is no longer widely used. SLIP provides a simple way to connect to the internet and is still used in some embedded systems.

PPP (Point-to-Point Protocol) is the most commonly used protocol for connecting to the internet. PPP provides a reliable, secure, and efficient way to transfer data over a network connection.

Service Options:

There are several service options available when connecting to the internet, including email, World Wide Web (WWW), and firewalls.

Email is a method for sending and receiving electronic messages over the internet. Email is a popular communication tool and is widely used for both personal and business communication.

The World Wide Web (WWW) is a system of interconnected documents and resources that are accessed using a web browser. The WWW provides access to a vast array of information and resources, including websites, online stores, and social media platforms.

Firewalls are a security measure that protects a network from unauthorized access. Firewalls can be hardware or software-based and are used to monitor and control network traffic. Firewalls are an essential component of network security and are used in both personal and business settings.

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Internet Connectivity & Setting up a connection | Lecture 9 &10 | M2

Setting up a connection, Hardware Requirement, selection of modem Setting up an internet connection requires a few hardware components, one of which is a modem. A modem is a device that connects your computer or router to your internet service provider's (ISP) network, allowing you to access the internet.

When selecting a modem, there are a few factors to consider:

1. Compatibility: Make sure that the modem you choose is compatible with your ISP's network. Some ISPs may only support specific models or types of modems.
2. Connection type: Different modems support different connection types, such as DSL, cable, or fiber. Choose a modem that is compatible with your connection type.
3. Speed: Make sure that the modem you choose can support the speed of your internet plan. If your plan offers high-speed internet, you will need a modem that can handle those speeds.
4. Features: Consider any additional features that you may need, such as a built-in router or Wi-Fi capabilities.

Here are some popular modem options to consider:

1. Cable modems: These modems are compatible with cable internet and offer high-speed connections. Some popular brands include Motorola, Netgear, and Arris.
2. DSL modems: These modems are compatible with DSL internet and are typically less expensive than cable modems. Popular brands include TP-Link, Netgear, and Zyxel.
3. Fiber modems: These modems are compatible with fiber internet and offer the highest speeds available. Popular brands include Nokia and Calix.

Ultimately, the modem you choose will depend on your specific needs and the compatibility with your ISP's network. Be sure to do your research and choose a reputable brand and model to ensure reliable internet connectivity.

Software requirement, modem configure & internet accounts by ISP

In addition to hardware requirements, setting up an internet connection also involves software requirements and configurations. Here are some steps to follow:

1. Obtain software from your ISP: Your internet service provider (ISP) may provide you with software to help you configure your modem and connect to their network. Be sure to download and install this software if it is available.
2. Connect your modem: Connect your modem to your computer or router using an Ethernet cable. Make sure that your modem is properly connected to your ISP's network by following the instructions provided by your ISP.
3. Configure your modem: You will need to configure your modem to connect to your ISP's network. Follow the instructions provided by your ISP to configure your modem.
4. Set up an internet account: Your ISP will provide you with an internet account, which will allow you to access the internet. Follow the instructions provided by your ISP to set up your internet account.
5. Test your connection: Once your modem is connected and configured, and your internet account is set up, you can test your connection to make sure that it is working properly. Open a web browser and try to access a website.

If you encounter any issues during the setup process, consult your ISP's documentation or contact their customer support for assistance.

It's also important to note that some ISPs may require additional steps or configurations, depending on their specific network requirements. Be sure to follow their instructions carefully to ensure a successful connection.

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Internet Connectivity and Its Levels | Lecture -8 | M2

Internet connectivity has become a fundamental requirement for individuals, businesses, and governments all over the world. It enables the exchange of information, communication, and collaboration on a global scale. However, not all internet connectivity is created equal. There are different types of connectivity that offer varying levels of speed, reliability, and cost-effectiveness. In this article, we will explore the three levels of internet connectivity: level one, level two, and level three.

Level One Connectivity

Level one connectivity refers to the highest level of internet connectivity available. It is also known as backbone or wholesale connectivity, and it is typically provided by global telecommunications companies such as AT&T, Verizon, and Level 3 Communications. These companies operate massive fiber optic networks that span continents and provide the backbone of the internet.

Level one connectivity is the most reliable and fastest form of internet connectivity. It enables high-speed data transmission between countries and continents, making it ideal for global businesses, research institutions, and governments. However, it is also the most expensive form of connectivity, and it is not available to most individuals or small businesses.

Level Two Connectivity

Level two connectivity is the middle tier of internet connectivity. It is also known as regional or metro connectivity, and it is typically provided by regional internet service providers (ISPs) or internet exchange points (IXPs). These companies connect to level one providers and offer connectivity to smaller regions or metropolitan areas.

Level two connectivity is less expensive than level one connectivity and is suitable for businesses and individuals that require high-speed internet connectivity within a specific region or city. It is also a good option for smaller ISPs or content providers that want to connect to multiple networks for redundancy and reliability.

Level Three Connectivity

Level three connectivity is the entry-level tier of internet connectivity. It is also known as local or last-mile connectivity, and it is typically provided by local ISPs or telecommunication companies. Level three connectivity is the most common type of internet connectivity and is what most individuals and small businesses use.

Level three connectivity is generally slower and less reliable than level one and level two connectivity. It is also less expensive, making it an affordable option for most people. However, level three connectivity can suffer from congestion during peak usage periods, leading to slow internet speeds and service disruptions.

Conclusion

Internet connectivity is essential for modern-day communication and collaboration. The three levels of connectivity - level one, level two, and level three - offer varying levels of speed, reliability, and cost-effectiveness. Level one connectivity is the highest tier and is suitable for global businesses and institutions. Level two connectivity is the middle tier and is suitable for regional connectivity. Level three connectivity is the entry-level tier and is suitable for local connectivity. Each level of connectivity offers different benefits and drawbacks, and it is essential to choose the level of connectivity that best suits your needs.

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Machine, Email and Resource Addressing | Lecture - 7 | M2

(Machine addressing)

Machine addressing is a fundamental concept in computer science and is essential for understanding how computers store and retrieve data. In this article, we will provide a detailed overview of machine addressing, including what it is, why it is important, and how it works.

What is Machine Addressing?

Machine addressing is the process by which a computer identifies the location of data in its memory. Every piece of data stored in a computer's memory has a unique address that can be used to locate and access it. These addresses are typically represented as binary numbers and are used by the computer's hardware to read and write data to and from memory.

Why is Machine Addressing Important?

Machine addressing is important for several reasons. First, it allows computers to store and retrieve data quickly and efficiently. Without machine addressing, computers would have to search through all of their memory to find the data they need, which would be incredibly slow and inefficient.

Second, machine addressing allows programs to access and manipulate data stored in memory. Programs can use the addresses of data to read or write to specific locations in memory, which is essential for performing operations such as sorting, searching, and data analysis.

Finally, machine addressing is important for security. By assigning unique addresses to each piece of data in memory, computers can ensure that data is stored and accessed only by authorized users. This helps to prevent unauthorized access to sensitive information and protects the privacy and security of computer users.

How Does Machine Addressing Work?

Machine addressing works by assigning a unique binary address to each piece of data stored in a computer's memory. This address is typically represented as a series of ones and zeros, with each digit representing a bit of information.

The size of the address space depends on the architecture of the computer's memory. For example, a 32-bit computer can address up to 4 gigabytes of memory, while a 64-bit computer can address up to 16 exabytes of memory.

When a program needs to read or write data to memory, it sends a request to the computer's hardware, which uses the address to locate the data in memory. The hardware then retrieves or stores the data at the specified address.

To ensure that data is stored and accessed correctly, computer systems use a variety of addressing modes. These modes determine how the computer's hardware interprets the address and how it retrieves or stores the data.

Some common addressing modes include direct addressing, indirect addressing, and indexed addressing. Direct addressing is the simplest form of addressing and involves using the address to directly access a specific location in memory. Indirect addressing involves using the address to access a pointer or reference to the data in memory. Indexed addressing involves using an index or offset to calculate the address of the data.

Conclusion

Machine addressing is a fundamental concept in computer science and is essential for understanding how computers store and retrieve data. By assigning unique addresses to each piece of data in memory, computers can access and manipulate data quickly and efficiently. Machine addressing is also important for security, as it helps to prevent unauthorized access to sensitive information. Understanding how machine addressing works is essential for anyone interested in computer science, programming, or data analysis.

(Email Addressing)

Email Addressing and Resource Addressing are two concepts that are fundamental to the functioning of the email system. In this article, we will provide a detailed overview of email addressing and resource addressing, including what they are, how they work, and why they are important.

Email Addressing

Email addressing is the process by which an email is sent from one person to another using the internet. It is a unique identifier that enables a person to receive email messages from other people. An email address typically consists of two parts: the username and the domain name.

The username is a unique identifier that identifies the user within the domain. It is usually an alphanumeric string that can include dots, hyphens, and underscores. The domain name is the part of the email address that identifies the domain of the email service provider. It typically consists of the company name or organization name, followed by a domain suffix, such as .com, .org, or .edu.

For example, in the email address siddiqi.ab26@gmail.com, " siddiqi.ab26" is the username, and "gmail.com" is the domain name. This email address identifies Siddiqi as a user of the Gmail email service provided by Google.

(Resource Addressing)

Resource addressing is a way of identifying a specific resource or location within a domain. It is commonly used in email systems to identify specific email messages or folders within a mailbox. Resource addressing uses a special character, called the hash symbol (#), to separate the resource identifier from the rest of the address.

For example, in the email address siddiqi.ab26@gmail.com#inbox, "siddiqi.ab26@gmail.com" is the email address, and "#inbox" is the resource identifier that identifies the inbox folder within Siddiqi's mailbox.

Resource addressing is important because it allows email clients to identify and retrieve specific resources within a domain, such as email messages or folders. This makes it easier for users to organize and manage their email messages.

Conclusion

Email addressing and resource addressing are essential concepts in the email system. Email addressing enables people to send and receive email messages using unique identifiers, while resource addressing allows users to identify and retrieve specific resources within a domain. By understanding these concepts, users can effectively manage their email messages and ensure that they are sent to the correct recipients.

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Router | Lecture - 6 | M2

A router is a networking device that connects multiple computer networks together and forwards data packets between them. It is a key component of the internet infrastructure and is used to route data between local area networks (LANs), wide area networks (WANs), and the internet. In this article, we will explore the functions, types, and key features of routers.

Functions of a Router: 

A router performs two main functions: packet forwarding and routing. Packet forwarding involves transferring data packets between different networks. Routing involves determining the best path for data packets to take as they travel through the network. The router analyses the destination address of each data packet and decides which network to send it to based on its routing table.

Types of Routers: There are several types of routers available in the market, including:

1. Wired Router: A wired router connects devices to a network using Ethernet cables. This type of router is often used in small office or home environments.
2. Wireless Router: A wireless router uses radio waves to connect devices to a network. This type of router is often used in homes and small offices.
3. Core Router: A core router is used in the backbone of the internet to route data packets between large networks.
4. Edge Router: An edge router is used to connect small to medium-sized networks to the internet.
5. Virtual Router: A virtual router is a software-based router that runs on a virtual machine or a cloud-based platform.

Key Features of a Router:

1. Firewall: Many routers include a built-in firewall that helps protect the network from external threats.
2. Quality of Service (QoS): QoS is a feature that allows routers to prioritize certain types of traffic, such as video or voice, to ensure that they receive sufficient bandwidth.
3. VPN Support: VPN support allows remote users to securely connect to a network over the internet.
4. Bandwidth Control: Bandwidth control allows network administrators to limit the amount of bandwidth that certain devices or applications can use.
5. Parental Controls: Many routers include parental controls that allow parents to restrict access to certain websites or applications.

Conclusion: Routers are an essential component of modern computer networks. They perform the critical function of forwarding data packets between different networks and ensuring that they reach their intended destination. There are several types of routers available, including wired, wireless, core, edge, and virtual routers. Key features of routers include firewalls, quality of service, VPN support, bandwidth control, and parental controls. When selecting a router, it is essential to consider the type of network and the specific features that are required to meet the needs of the network's users.

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Internet protocols: TCP/IP | Lecture - 5 | M2

TCP/IP, which stands for Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet. It is the most widely used networking protocol in the world, and it forms the backbone of the internet.

TCP/IP is actually a combination of two protocols: the TCP protocol and the IP protocol. The IP protocol is responsible for routing packets of data from one device to another across the internet, while the TCP protocol is responsible for ensuring that the data is transmitted reliably and error-free.

TCP/IP has four layers, each with a specific function. These layers are:

1.  Application Layer: This layer is responsible for providing applications with access to the network. Examples of protocols in this layer include HTTP, FTP, SMTP, and Telnet.
2. Transport Layer: This layer is responsible for providing reliable data transfer between devices. The two protocols in this layer are TCP and UDP. TCP provides reliable, ordered, and error-checked delivery of data between applications running on different hosts, while UDP provides unreliable, unordered, and unverified delivery of data.
3. Internet Layer: This layer is responsible for addressing and routing data packets between devices on different networks. The IP protocol operates at this layer.
4. Network Access Layer: This layer is responsible for transmitting data between devices on the same network. Examples of protocols in this layer include Ethernet, Wi-Fi, and Bluetooth.

TCP/IP has several advantages, which have contributed to its widespread adoption. These include:

1. Compatibility: TCP/IP is compatible with a wide range of operating systems, network devices, and applications, which makes it the preferred choice for network communication.
2. Scalability: TCP/IP can be scaled up or down to meet the needs of different networks, from small local area networks (LANs) to large wide area networks (WANs) spanning entire continents.
3. Reliability: TCP/IP provides reliable data transfer, which ensures that data is transmitted without errors and is received in the correct order.
4. Security: TCP/IP has several built-in security features, such as IPsec, which provides encryption and authentication of data packets.

In summary, TCP/IP is a suite of communication protocols that provides reliable and efficient communication between devices on the internet. It is the backbone of the internet and is used by millions of people around the world every day.

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Packet Switching Technology | Lecture – 4 | M2

Packet switching technology is a fundamental aspect of modern computer networks, enabling the efficient transmission of data over the Internet and other digital communication networks. In this article, we will explore the basics of packet switching technology, how it works, and its benefits over other forms of data transmission.

Packet Switching Technology Overview

Packet switching technology is a method of transmitting data over a network by breaking it down into small units called packets. Each packet contains a header that includes information about the sender and receiver, as well as the packet's position within the overall data transmission. The data payload, or the actual data being transmitted, is also included in the packet.

When a device wants to transmit data over a network, it breaks the data into packets and sends them over the network. Each packet is routed independently through the network to its destination. When the packets arrive at their destination, they are reassembled into the original data transmission.

Packet switching is different from circuit switching, which establishes a dedicated communication channel between two devices for the duration of the communication. In packet switching, multiple devices can share the same communication channel, and packets are routed through the network dynamically based on the most efficient path available at the time.

How Packet Switching Works

Packet switching technology works by breaking data transmissions into smaller packets and routing them independently through the network. When a device wants to transmit data, it first divides the data into packets of a fixed size. The size of packets can vary depending on the network and the type of data being transmitted, but typical sizes range from 64 bytes to 1,500 bytes.

Each packet is then given a header that includes information about the sender, the receiver, and the packet's position within the overall data transmission. The header also includes information about the type of packet, such as whether it is a control packet or a data packet.

Once the packets are ready, they are sent over the network. The network uses routers and switches to route the packets to their destination. Each router examines the packet header to determine the best path for the packet to take to reach its destination. The router then forwards the packet to the next router or directly to the destination device.

When the packets arrive at their destination, they are reassembled into the original data transmission. The destination device examines the packet headers to determine the order in which the packets should be reassembled.

Benefits of Packet Switching Technology

Packet switching technology offers several benefits over other forms of data transmission, including:

Efficient use of network resources: Packet switching technology allows multiple devices to share the same communication channel, enabling more efficient use of network resources.

Better reliability: In packet switching, if a packet is lost or corrupted during transmission, only that packet needs to be retransmitted, rather than the entire data transmission.

Ability to handle variable data rates: Packet switching technology can handle data transmissions of different sizes and rates, making it ideal for transmitting different types of data, including voice, video, and data.

Cost-effective: Packet switching technology is more cost-effective than other forms of data transmission, such as circuit switching, as it requires less infrastructure.

Conclusion

Packet switching technology is a fundamental aspect of modern computer networks, enabling the efficient transmission of data over the Internet and other digital communication networks. By breaking data transmissions into smaller packets and routing them independently through the network, packet switching technology enables more efficient use of network resources, better reliability, and the ability to handle variable data rates.

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