Internet Service Providers (ISPs)

- Overview

The internet backbone is the core infrastructure for internet traffic, consisting of high-capacity networks and routers that facilitate data exchange between large networks, including those of internet service providers (ISPs). 

ISPs connect to these backbones, allowing their users to access the global internet through a complex system of interconnection protocols. 

The internet backbone can be defined by the primary data routes between large, strategically interconnected computer networks and the internet's core routers. These data routes are hosted by commercial, government, academic, and other high-capacity network hubs (i.e., internet exchange points and network access points), which exchange internet traffic across countries, continents, and oceans. 

Almost all web browsing, video streaming, and other common online traffic flows through internet backbones. They are composed of network routers and switches connected primarily by fiber-optic cables. Each fiber link in the backbone typically provides 100 Gbps of network bandwidth. Computers are rarely connected directly to the backbone. Instead, the networks of ISPs or large organizations connect to these backbones, and computers access them indirectly. 

ISPs participate in internet backbone traffic through privately negotiated interconnection agreements, which primarily follow the principle of settlement-free peering. The interactions between large enterprises and the agreements under which they share networks often create complex business dynamics.

Key characteristics:

• Internet Backbone: The internet backbone is the principal network of high-speed, long-distance data routes. These routes are hosted by various entities including commercial, governmental, and academic institutions, and they connect at Internet Exchange Points and Network Access Points.
• ISP Participation: ISPs connect to the internet backbone through interconnection agreements, often involving settlement-free peering, where they exchange traffic without financial settlements. These agreements also involve complex business relationships between large corporations.
• Indirect Connection: End-users and organizations rarely connect directly to the backbone. Instead, their access to the internet is facilitated by ISPs, which connect to the backbone and provide internet access to their users.
• Backbone Structure: The backbone itself is made up of interconnected networks, primarily using fiber optic cables and high-speed routers. Each fiber optic connection can carry substantial bandwidth, often 100 Gbps.
• Tiered Structure: The internet can be conceptualized with a tiered structure, with Tier 1 ISPs having direct access to the backbone, and Tier 2 and Tier 3 ISPs connecting to the backbone indirectly through other providers.

- The Internet Has Transformed The World

The internet has fundamentally transformed every aspect of life, including communication, access to information, business practices, and social interactions. It provides unprecedented global connectivity, enabling people to connect with others across borders, share information instantly, and access vast amounts of knowledge. 

However, its impact is complex, with both positive and negative consequences, including concerns about privacy, online harassment, and the spread of misinformation. 

It is difficult to quantify how the internet has changed the world. It has transformed business, education, government, healthcare, and even the way we interact with our loved ones—it has become a key driver of social evolution. Changes in social communication are particularly significant. The internet has eliminated all barriers to communication. 

The internet has also transformed our perceptions of time, space, and distance. It has created new communities, connecting people from all over the world. Of course, the internet also means that anonymous trolls can spread hate speech on social media, and that overseas bots can post negative and false tweets against politicians and celebrities, inciting anger, resentment, and even violence. 

While businesses of all sizes are leveraging the internet to streamline supply chain management and connect customers more closely to their brands, they also have to contend with hackers stealing customer financial information, or competitors and nation-states spreading negative online reviews or using the internet to spy on their product plans or finances. Privacy, or the increasing vulnerability of privacy, has also become an issue because of the internet—or, more accurately, how we use it. 

The key internet's impacts:

• Communication: The internet has revolutionized communication by allowing for near-instantaneous communication through email, social media, and video calls, facilitating global connection and breaking down geographical barriers.
• Information Access: The internet has democratized access to information, providing individuals with access to vast libraries of knowledge, news, and resources that were previously limited.
• Business: The internet has transformed business operations, enabling online shopping, e-commerce, and global marketing. It has also created new industries and business models.
• Education: The internet has expanded educational opportunities by enabling online learning and providing access to courses and materials from around the world.
• Healthcare: The internet has improved healthcare access by allowing patients to research health information, communicate with doctors virtually, and access medical records electronically.
• Social Impact: The internet has created new communities and fostered connections between people with shared interests. However, it has also contributed to the spread of misinformation, hate speech, and cyberbullying.
• Privacy Concerns: The increasing use of the internet has raised concerns about privacy, as personal data is collected and shared by companies and online platforms.

Please refer to following for more information:

• Wikipedia: Tier 1 Network
• Wikipedia: Tier 2 Network

- The Digital "Self" and Constant Connectivity

The internet is becoming increasingly personalized and interconnected, tracking our online activities and using this information to target us with advertising and marketing, essentially creating a digital "self" that is more entwined with our daily lives than ever before. This can raise concerns about privacy and potential addiction to online platforms. 

The increasing personalization and interconnectedness of the internet, while offering benefits, raise serious concerns about online privacy, the potential for corporate manipulation, and the impact of constant connectivity on our mental well-being and the formation of our digital identities. 

Understanding these dynamics and actively engaging in discussions about regulating data practices, promoting digital literacy, and prioritizing user control and agency is crucial for navigating this evolving digital landscape responsibly.

• Privacy: The extensive data collection raises concerns about the potential for misuse, unauthorized access, and lack of control over our personal information.
• Corporate Manipulation: The ability to gather and analyze vast amounts of behavioral data enables companies to predict and potentially influence user behavior, raising questions about manipulation and consumer autonomy.
• Mental Health: Constant connectivity, the pressure to maintain an online persona, and social comparison fueled by curated social media feeds can negatively impact mental health, leading to increased anxiety, depression, and low self-esteem.
• Addiction: The design of online platforms, particularly social media, with features like infinite scrolling and personalized notifications, can trigger dopamine-driven reward systems in the brain, contributing to addictive behaviors and difficulties in regulating usage.

- The Roles and Responsibilities of ISP

An Internet Service Provider (ISP) is a company that provides internet access to individuals and businesses. ISPs act as bridges, connecting users to a vast network of online resources. They offer a variety of services, including web access, email, website hosting, and more. 

ISPs use a variety of technologies, including fiber optics, satellite, and copper wire, to provide internet access to individuals and businesses. ISPs connect to each other to form a network, with the backbone serving as the primary communications highway. 

These connections support high-speed data transfers, useful for tasks like email, streaming, and online gaming. 

ISPs are categorized into different tiers, with Tier 1 ISPs having the broadest global coverage, and Tier 2 and 3 ISPs building upon this coverage.

Key aspects:

• Access Providers: Most ISPs are access providers, using technologies like DSL, cable, fiber optics, or satellite to deliver internet to homes and businesses.
• Network Infrastructure: ISPs handle the routing of internet traffic, domain name resolution, and network infrastructure maintenance.
• Tiered Structure: ISPs are categorized into tiers based on their network reach and connectivity. Tier 1 ISPs have global reach, while Tier 2 and Tier 3 ISPs connect to them and each other.
• Backbone Networks: ISPs connect through backbone networks, which act as the main communication pathways for data transfer.
• Media Types: ISPs utilize various media like fiber optic cables, satellite connections, and copper wires to connect users to the internet.

- Understanding ISP's Tiers

Internet Service Providers (ISPs) are categorized into a tiered structure, each serving a distinct role in providing internet access. 

The tiered structure of ISPs ensures a vast, interconnected network where Tier 1 ISPs provide the global backbone, Tier 2 ISPs bridge the gap to regional access, and Tier 3 ISPs deliver the internet directly to homes and businesses, utilizing a combination of peering and transit agreements and various access technologies to ensure a seamless internet experience for users worldwide.

Tier 1 ISPs:

• Global Backbone: Tier 1 ISPs form the backbone of the internet, possessing extensive global reach and operating massive network infrastructure, including undersea cables and data centers. They are the "movers and shakers" of the industry.
• Settlement-free Peering: Tier 1 ISPs engage in settlement-free peering agreements with other Tier 1 providers, exchanging traffic without needing to pay for it. This eliminates transit costs and ensures direct, efficient data paths.
• Infrastructure: Tier 1 networks utilize high-capacity fiber optic cables and core routers in a full-mesh topology, ensuring redundancy and scalability. Examples include AT&T, Verizon, CenturyLink (now Lumen Technologies), and NTT Communications.

Tier 2 ISPs: 

• Regional/National Focus: Tier 2 ISPs operate on a regional or national scale, connecting end-users and businesses to the wider internet.
• Peering and Transit: They peer with other Tier 2 ISPs and purchase IP transit from Tier 1 ISPs to reach the broader internet. According to HotBot, Tier 2 ISPs also often engage in both peering and transit arrangements.
• Services: Tier 2 ISPs commonly offer a range of services, including cloud solutions, VoIP, and content delivery.
• Infrastructure: Their infrastructure includes network nodes, sophisticated routing equipment, backbone links, and redundancy mechanisms to ensure reliable data transmission within their regions. Examples include Comcast, Cox, and Telia Carrier.

Tier 3 ISPs:

• Local Focus/Last Mile: Tier 3 ISPs are typically regional or local providers, specializing in delivering internet access directly to end-users (residential and businesses) in specific geographic areas.
• Reliance on Higher Tiers: They often lease bandwidth and network access from Tier 1 or Tier 2 ISPs to connect their customers to the global internet.
• Customer-Focused Services: Tier 3 ISPs may emphasize local customer support and offer tailored services to their local markets.
• Limited Infrastructure: Unlike higher tiers, Tier 3 ISPs have limited network infrastructure and primarily focus on the "last mile" connectivity to end-users, according to Lightyear.ai.

Interconnection and the Internet Backbone:

• IXPs: ISPs interconnect at Internet Exchange Points (IXPs), data centers, or through private peering arrangements.
• Fiber Optics: Interconnections predominantly rely on high-speed fiber optic cables, which offer faster transmission and lower signal loss compared to copper wire.
• Shared Infrastructure: The collective network of interconnected ISPs forms the internet backbone, enabling global connectivity and the efficient exchange of data.

- The Roles and Responsibilities of Tier 1 ISPs

At the very top of the hierarchy, Tier 1 ISPs own the infrastructure that forms the backbone of the Internet. Each Tier 1 ISP has a peering agreement with every other Tier 1 ISP. This means that they agree to forward and receive traffic from each other without charging the other ISP for it. 

Tier 1 ISPs have access to the Internet routing table, also known as the global routing table. What this means that they know the top-level ISP to which any IP address should be sent. They also know which of their lower-tier ISPs receive any given IP address. As such, there is no concept of a “default route” at this level. 

With lower-tier ISPs, a router can give up if it does not know where a certain packet should go and just send it to a higher-level ISP. Tier 1 ISPs do not pay for data transit. 

Tier 1 providers, such as AT&T, Verizon, and CenturyLink, own the infrastructure and manage traffic across continents. 

The key roles and responsibilities of ISPs: 

Core Functions:

• Backbone Connectivity: Tier 1 ISPs own the physical infrastructure (fiber optic cables, routers, etc.) that forms the foundation of the internet.
• Global Routing: They have access to the global routing table, allowing them to determine the optimal path for data to travel across networks.
• Peering Agreements: Tier 1 providers have agreements with each other, allowing them to exchange traffic without paying transit fees.
• No Default Route: Unlike lower-tier ISPs, they don't rely on a default route to forward traffic; they know the exact path for each IP address.

Responsibilities: 

• Maintaining Global Reach: Tier 1 ISPs ensure connectivity between different regions and countries, facilitating global communication.
• Efficient Traffic Routing: They optimize data flow across their networks to minimize latency and ensure reliable service.
• Supporting Other ISPs: Tier 1 ISPs provide connectivity and support to lower-tier ISPs, enabling them to reach the global internet.
• Infrastructure Development: They invest in and maintain the high-capacity infrastructure needed for the internet's continued growth and performance.

Key Characteristics: 

• Global Scope: Tier 1 ISPs have extensive networks that span continents.
• Settlement-Free Peering: They exchange traffic with each other without incurring fees.
• Access to the Global Routing Table: This allows them to make informed routing decisions.
• No Reliance on Default Route: They have detailed knowledge of network paths, unlike lower tiers.

- The Roles and Responsibilities of Tier 2 ISPs

Tier 2 ISPs purchase internet access (IP transit) from Tier 1 ISPs and other Tier 2 ISPs, and may also peer with other networks for cost savings. They then resell this internet access to their own customers, often focusing on a regional or national scope. 

Examples include Comcast, British Telecom, Vodafone, and Sprint Communications. 

Key Responsibilities and Characteristics:

• Purchase IP Transit: Tier 2 ISPs buy bandwidth from Tier 1 providers, essentially paying to connect to the broader internet.
• Peering Agreements: They establish peering relationships with other Tier 2 ISPs to exchange traffic directly, bypassing the need to go through Tier 1 networks for all traffic.
• Reselling Internet Access: Tier 2 ISPs sell internet service to end-users, including residential customers, businesses, and potentially even other smaller ISPs (Tier 3).
• Regional/National Focus: Tier 2 networks typically have a more limited geographic reach compared to Tier 1 networks, often operating within a region or country.
• Bridging the Gap: Tier 2 ISPs act as a bridge between the global reach of Tier 1 networks and the more localized needs of Tier 3 ISPs and end-users.
• Innovation: Tier 2 ISPs are often at the forefront of innovation in internet services, including cloud-based models and Network-as-a-Service (NaaS) solutions.
• Network Management: Tier 2 ISPs manage and maintain their own network infrastructure to ensure service quality and reliability for their customers.

- The Roles and Responsibilities of Tier 3 ISPs

A Tier 3 network refers to the lowest level of Internet Service Providers (ISPs). They are typically local providers who offer internet access to end-users (homes and businesses) but rely on higher-tier providers (Tier 1 and Tier 2) for their connectivity to the broader internet. 

Tier 3 networks are essential for providing local internet access to end-users, but they rely on higher-tier networks for their connectivity to the global internet.

A packet will often pass through several networks en route to its destination, both within and between ISPs. Each link terminates at a router which makes a decision on where the packet should be delivered. Each transmission of a packet is called a hop. 

Within ISPs, edge routers are placed at the edge of an ISP’s network and communicate with other networks. For larger organizations, an edge router may sit at the edge of a customer’s network and connect to one or more ISPs. 

A core router is a router that connects routes on the Internet backbone. A core router may also be used in dispersed organizations to interconnect routers from multiple locations.

Key characteristics of Tier 3 networks: 

• Local Focus: Tier 3 ISPs primarily serve a local or regional area, delivering internet access to end-users within that specific geographic area.
• Reliance on Higher Tiers: They don't own the extensive global infrastructure of Tier 1 or Tier 2 networks. Instead, they purchase bandwidth and connectivity from these higher-tier providers.
• "Last Mile" Providers: Tier 3 ISPs are often considered "last mile" providers, as they handle the final connection between the internet backbone and the end-user's location.
• Cost-effective for End-users: They offer a more affordable option for internet access, as they don't need to invest heavily in global infrastructure.
• Examples: Rural telecoms, local internet companies, and small managed IT services companies often operate as Tier 3 ISPs.

In contrast to higher-tier ISPs: 

• Tier 1 ISPs: Own the largest global networks and have peering relationships with each other, allowing free exchange of internet traffic.
• Tier 2 ISPs: Purchase bandwidth from Tier 1 providers and may also peer with other Tier 2 networks. They optimize traffic for businesses and local ISPs.

[More to come ...]