Internet Bandwidth Protocols

Connecting to the Internet is a multistage process requiring coordination between the user's computer, the Internet provider, and the provider's connection with the backbone (via a NAP). Each connection may operate at a different speed utilizing a variety of protocols. Below are several of the most common.

1. PPP: PPP (point-to-point protocol) is the standard dial-up connection protocol for Internet access today. It is used to connect modems of up to 56Kb to Internet Service Providers (ISP) who have matching modems on their side of the network.
2. ISDN: ISDN or Integrated Services Digital Network is the basic rate connection that operates over regular phone lines and can transmit data at speeds of 128 Kbps. ISDN uses special switching techniques to obtain higher bandwidth from telephone lines. It provides dedicated connections. However, telecommunications companies never widely delivered ISDN, so ISDN is now being replaced by DSL (Digital Subscriber Line).
3. X.25: X.25 is the widely used protocol for WAN (wide area network) networking, especially outside the U.S. in low-speed applications such as credit card verification. It provides communication service for transmitting data over error-prone facilities. For error checking, it performs checks at each node. However, it cannot process real-time voice or video.
4. Frame relay: Frame relay is a high-speed networking protocol with a bandwidth size larger than ISDN and as large as T1. It's generally a lower-cost way of providing T1-level service when the demand for the full speed (1.54 Mb/sec) is not severe. Like X.25, frame relay is a packet switched protocol that can transmit packets over a WAN at speeds from 56 Kbps-45 Mbps.
5. Asynchronous Transfer Mode (ATM): Asynchronous Transfer Mode (ATM) is a fixed size, very high-capacity cell switching technology that divides data into 53-byte packets called cells and transmits them at speeds from 25-622 Mbps. Traditionally, ATM has been used to create high-speed neworks in financial applications such as Automated Teller Machines (ATMs).

The functionality and robustness of the Internet are predicated on a suite of protocols, each designed to fulfill specific roles within the network's ecosystem. These protocols work in concert to facilitate seamless connectivity, communication, and data exchange across the Internet. Herein, we delineate the pivotal protocols that underpin Internet connectivity:

1. Internet Protocol (IP):
   • Function: IP is the cornerstone of the Internet, providing a standardized method for addressing and routing packets of data to ensure they reach their intended destination. IP addresses, unique numerical labels, are assigned to devices connected to the network, facilitating their identification and communication.
   • Versions: IPv4 and IPv6 are two versions of IP, with IPv6 introduced to address the exhaustion of IPv4 addresses by offering a vastly larger address space.
2. Transmission Control Protocol (TCP):
   • Function: TCP works closely with IP (together referred to as TCP/IP) to ensure reliable data transmission between devices. It establishes connections, manages data packet sequencing, and implements error checking and correction to guarantee the integrity and order of data packets.
3. User Datagram Protocol (UDP):
   1. Function: Unlike TCP, UDP is connectionless, offering a faster data transmission method by eliminating the error-checking and recovery processes. This makes UDP suitable for time-sensitive applications where occasional data packet loss is acceptable, such as live video or audio streaming.
4. Hypertext Transfer Protocol (HTTP) and HTTPS:
   • Function: HTTP is the protocol used for transferring web pages on the Internet. It operates over TCP to communicate between web servers and clients (browsers). HTTPS (HTTP Secure) is the encrypted version of HTTP, utilizing Transport Layer Security (TLS) or its predecessor, Secure Sockets Layer (SSL), to provide secure communication over a computer network.
5. Simple Mail Transfer Protocol (SMTP):
   • Function: SMTP is the standard protocol for email transmission across the Internet. It is used to send messages from an email client to a server or between servers for forwarding emails to their final destination.
6. Post Office Protocol (POP) and Internet Message Access Protocol (IMAP):
   • Functions: POP and IMAP are used for email retrieval from a server. POP downloads emails from a server to a client and typically deletes them from the server. In contrast, IMAP allows for managing and viewing emails directly on the server, facilitating access from multiple devices.
7. Domain Name System (DNS):
   • Function: DNS is a hierarchical and decentralized naming system used to translate human-readable domain names (like www.example.com) into IP addresses that networking equipment use for routing decisions. It functions like an Internet "phone book."
8. Dynamic Host Configuration Protocol (DHCP):
   • Function: DHCP automates the assignment of IP addresses, subnet masks, gateways, and other IP networking parameters by dynamically allocating them to devices on a network, simplifying the management of IP address configurations.
9. File Transfer Protocol (FTP) and Secure File Transfer Protocol (SFTP):
   • Function: FTP is used for the transfer of files between a client and a server on a network. SFTP, an extension of Secure Shell protocol (SSH), provides secure file transfer capabilities.
10. Transport Layer Security (TLS) and Secure Sockets Layer (SSL):
    • Function: TLS and SSL are cryptographic protocols designed to provide secure communication over a computer network. They are widely used for securing web traffic, ensuring that data transmitted between web browsers and servers remains encrypted and secure.

Each of these protocols plays a specialized role within the Internet's architecture, facilitating various aspects of connectivity, data transmission, security, and services. Together, they form the backbone of the Internet, enabling the myriad functionalities and applications that define the modern digital experience.

In the context of data communication, padding refers to the practice of adding extra data to the contents of a message or data block to align it to a certain size or length requirement. This is often necessary because certain encryption algorithms, protocols, or data storage mechanisms require input to be of a specific length.
Here are several contexts in which padding is used:

1. Block Cipher Encryption: In encryption, padding is added to plaintext to make it a multiple of the block size required by the encryption algorithm. For instance, if a block cipher like AES requires 128-bit blocks but the plaintext is not a multiple of 128 bits, padding is added to fill out the last block.
2. Data Alignment in Memory: Padding can also be used in data structures to align data in memory. For instance, in C programming, structures may have padding bytes inserted between members to ensure that each member is aligned on an appropriate memory boundary.
3. Network Packet Construction: Protocols may require that packets be a certain size, and if the message content does not fill out the full packet, padding is added to meet the size requirement.
4. Digital Signal Processing: In signal processing, padding with zeros, known as zero-padding, is often used when performing operations such as Fast Fourier Transform (FFT) to match the required input length.

The content of the padding can be predetermined (like zeros or a pattern), random, or could be designed in such a way that it can be easily removed (unpadded) upon decryption or receipt, which is known as padding scheme. Common padding schemes include

1. PKCS#7,
2. ANSI X.923, and
3. ISO/IEC 7816-4.

Padding can also include metadata to ensure that the original data can be perfectly reconstructed without ambiguity.
In the next lesson, the calculation of data transfer speed will be discussed.

Click the Quiz link bellow to review your understanding of internet bandwidth technologies and their protocols.
Internet Technologies Quiz