Internet Infrastructure

(Niagara Fall, Canada - Wei-Jiun Su)

• Cables: Fiber optic cables, both terrestrial and undersea, transmit data over long distances. 
• Servers: Powerful computers that store and deliver data and applications to users.
• Routers: Devices that direct data traffic between networks, ensuring data reaches the correct destination.
• Switches: Devices that connect devices within a local network, managing data flow between them.
• Cables and Wireless Access Points: Physical and wireless connections that transmit data between devices and networks. 
• Internet Exchange Points (IXPs): Locations where different networks connect and exchange traffic.
• Data Centers: Physical locations that house servers, storage, and networking equipment, providing a centralized location for internet infrastructure. 
• Network Interface Cards (NICs): Hardware components that enable devices to connect to a network.

2. Transmission Media: 

• Fiber Optic Cables: Used for high-speed data transmission over long distances.
• Satellite Links: Provide internet access to remote areas and can supplement terrestrial networks.
• Wireless Networks: Used for connecting devices to local networks and the internet.

3. Software Components: 

4. Protocol Components:

• TCP/IP: The core protocol suite that governs how data is broken down into packets, addressed, routed, and reassembled on the receiving end. 
• HTTP/HTTPS: Enables web browsing by defining how web pages are requested and displayed, with HTTPS providing secure, encrypted communication. 
• DNS: Translates human-readable domain names (like google.com) into machine-readable IP addresses. 
• FTP: Facilitates file transfer between computers on a network. 
• SMTP: Handles email transmission. 
• SSH: Provides secure remote access to servers and network devices. 
• DHCP: Automatically assigns IP addresses to devices on a network. 
• Security Protocols: SSL and TLS encrypt data transmitted over the internet, ensuring confidentiality and integrity. 

5. Other Essential Components: 

• Internet Exchange Points (IXPs): Physical locations where different networks connect and exchange traffic, facilitating internet connectivity.
• Content Delivery Networks (CDNs): Distributed networks of servers that store and deliver content, improving website loading times and performance.
• Domain Name System (DNS): A system that translates domain names (like google.com) into IP addresses, allowing users to access websites by name.

6. Key Functions: 

• Hosting and Storage: Data centers and servers store the vast amounts of information that make up the internet.
• Processing and Serving: Servers process requests and deliver content to users.
• Routing and Transmission: Protocols and infrastructure elements ensure data is routed efficiently and reliably.
• Connectivity: Provides the means for users to connect to the internet and access its resources.

- Internet Architectural Principles

The key architectural principle of the internet is that it does not rely on central control, instead placing most processing and decision-making on the communicating devices (end-to-end principle), resulting in a highly scalable and resilient network with no single point of failure. 

This decentralized approach, combined with its evolutionary growth and ability to adapt to new technologies and demands, has been crucial to the internet's success. 

Key points about the Internet architecture: 

• Decentralized control: No single entity manages the entire internet, allowing for flexibility and diverse participation.
• End-to-end principle: The responsibility for data integrity, reliability, and authentication lies with the communicating devices, not the network infrastructure.
• Scalability: The internet architecture can easily accommodate new networks and users without compromising its overall functionality.
• Resilience: The distributed nature of the internet means that even if one part of the network fails, data can still flow through other paths.
• Evolutionary growth: The internet has developed gradually through innovation and adaptation, rather than following a predetermined plan.

Important aspects of the modern internet backbone: 

• Multiple, redundant networks: The internet backbone consists of a network of interconnected fiber optic cables owned by different companies, ensuring high capacity and redundancy.
• High-bandwidth capacity: The backbone utilizes advanced fiber optic technology to handle the increasing volume of internet traffic.
• Dynamic routing: Sophisticated routing protocols allow the network to adjust traffic flow in real-time to optimize network performance and reroute traffic in case of failures.

(Photo: Princeton University, Office of Communications)

- How Internet Infrastructure Works

Internet infrastructure, including transmission media such as fiber optic cables, satellites, microwave (line of sight) antennas, routers, aggregators, repeaters, load balancers, and other network components that control transmission paths. 

The internet is a global network of networks, not owned by any single entity, but maintained and monitored by various organizations. 

Internet infrastructure, including physical hardware and software, is primarily designed, built, and operated by Internet Service Providers (ISPs) like Verizon and AT&T, who connect businesses and individuals to the internet through data centers. 

The Internet Society, a non-profit, establishes policies and protocols for internet usage. 

Key Aspects of Internet Infrastructure: 

• No Single Owner: The internet's decentralized nature means no single entity owns it, but rather it's a collaborative network of networks.
• ISPs: Companies like Verizon and AT&T are examples of ISPs that build, operate, and maintain the physical infrastructure, including transmission media (fiber optic cables, satellites, etc.), routers, and other network components.
• Data Centers: Businesses connect to the internet through ISPs, who often utilize data centers for secure and dedicated spaces to house their infrastructure.
• Internet Society: This non-profit organization sets the standards and protocols that govern how the internet functions, ensuring interoperability and global connectivity.

- The Internet Backbone

The Internet backbone is a conglomeration of multiple, redundant networks owned by numerous companies. It is typically a fiber optic trunk line. The trunk line consists of many fiber optic cables bundled together to increase the capacity. The backbone is able to reroute traffic in case of a failure. The data rates of backbone lines have increased over time. 

Fiber-optic cables are the medium of choice for Internet backbone providers for many reasons. Fiber-optics allow for fast data speeds and large bandwidth; they suffer relatively little attenuation, allowing them to cover long distances with few repeaters; they are also immune to crosstalk and other forms of electromagnetic interference which plague electrical transmission. 

- Routing Technologies and Process

Routing is the process of selecting and defining paths for IP packet traffic within or between networks, and the process of managing overall network traffic. 

Large autonomous networks or the Internet may provide thousands of possible routes between destinations. As networks continue to grow in size to support mission-critical uses, routing becomes increasingly important and complex. 

Understanding the network travel paths of internal and external traffic can help administrators identify sources of latency and provide workarounds. 

The routing process begins when software on the host device uses the packet's content, destination, or purpose to select possible routes from a routing table. A routing table is a repository of all routes to all destinations used by a network. 

Routing tables can be created manually and "learned" by software as it observes network traffic, or they can be built from routing protocols.

Simple print jobs can be transmitted using static routing, where the host inserts a previously used route. Dynamic routing allows packets to be routed contextually based on network conditions or factors such as reliability, performance and security requirements.

Each path segment in the network has a metric assigned based on these factors. These metrics are shared with the host and other nodes, stored in routing tables and used for path selection.

A node is any device connected to a network, such as a switch or router.

- Future Internet - Future Advances and Emerging Issues

As the internet turns 50, the technology is only picking up steam and continuing to reinvent many aspects of our lives, from the way we do business, and the way we find dates and jobs, to the way we run for political office. 

The spark of the Internet was lit in 1969, but the Internet really began to transform our lives in the late ‘90s to early 2000s. The next 50 years may bring pervasive connectivity, brain-computer interfaces and walled-off areas of the Internet.

[More to come ...]