ISP

ISP, or Internet Service Provider, is a company or organization that provides individuals, businesses, and other entities with access to the internet. ISPs connect customers to the global internet backbone through various technologies, such as fiber-optic cables, DSL, cable, satellite, fixed wireless, or mobile networks.

ISPs handle not only connectivity but also services like email hosting, web hosting, domain registration, and sometimes content delivery or security features. They act as gateways between end users and the broader internet, managing traffic routing, IP address assignment (via DHCP), and often DNS resolution.

There are different tiers:

- Tier 1: Global backbone providers (own international networks)

- Tier 2: Regional providers that peer and pay for transit

- Tier 3: Local/retail ISPs serving end users

Early internet access was limited to universities and government.

Key milestones: - 1960s–1980s: ARPANET and academic networks; no commercial ISPs

- 1989–1991: The World (first commercial dial-up ISP) and PSInet launched

- 1990s: Commercial boom – AOL, CompuServe, EarthLink, and thousands of local dial-up providers

- Late 1990s–2000s: Broadband transition (DSL, cable modem) replaces dial-up

- 2000s–2010s: Fiber rollout, mobile broadband (3G/4G), consolidation of industry

- 2015: Net neutrality rules in many countries (later repealed in US)

- 2020s: Fiber expansion, fixed wireless (Starlink), 5G integration, and government broadband subsidies

The NSFNET decommissioning in 1995 fully opened the internet to commercial ISPs.

An ISP connects customers to the internet through a multi-step infrastructure:

1. Customer premises equipment (modem/router) connects via access network 2. Traffic aggregates at local exchange or base station 3. Data routes through ISP’s core network to peering/transit points 4. Interconnects with other ISPs at Internet Exchange Points (IXPs) 5. Reaches destination servers via global backbone

ISPs use BGP (Border Gateway Protocol) for routing between networks, obtain IP blocks from regional registries (RIRs like RIPE, ARIN), and often operate their own DNS resolvers. They may throttle, block, or prioritize traffic based on policy or regulation.

Fiber and 5G fixed wireless are the fastest-growing segments.

Major global and regional ISPs: - United States: Comcast (Xfinity), Charter Spectrum, AT&T, Verizon Fios, T-Mobile Home Internet - Europe: Deutsche Telekom, Orange, Vodafone, BT - Asia: China Mobile, Reliance Jio (India), NTT (Japan) - Satellite: Starlink (SpaceX), OneWeb - Backbone/Tier 1: Level 3 (Lumen), Cogent, Tata Communications, Hurricane Electric

Regulatory bodies: FCC (US), Ofcom (UK), BEREC (EU). Industry groups like ISOC and regional internet registries (RIRs) coordinate addressing and policy.

ISPs enable: - Home and mobile internet access - Business connectivity and cloud services - Streaming video, gaming, remote work - IoT and smart home devices - Public Wi-Fi and community networks - Hosting and colocation services (for larger ISPs)

Many offer bundled TV/phone, VPNs, cybersecurity, or parental controls.

ISPs face ongoing issues: - Digital divide: Rural and low-income areas lack high-speed access - Net neutrality debates: Prioritization or throttling of traffic - Data caps and overage fees - Privacy concerns: Logging and selling user data - Infrastructure costs and monopolies in many regions - Vulnerability to outages (fiber cuts, DDoS, natural disasters) - Regulatory battles over competition and universal service

Consolidation has reduced choices in many markets.

ISPs are evolving with: - Widespread fiber and 5G deployment - Edge computing and CDN integration for lower latency - Zero-rating and sponsored data plans - IPv6 adoption (now majority of traffic) - Community and municipal broadband initiatives - Low-Earth-Orbit satellite competition disrupting traditional models - AI-driven network management and predictive maintenance

With remote work and high-bandwidth applications, reliable gigabit service is becoming standard in urban areas.

Internet Service Providers are the essential bridge connecting users to the global internet. From humble dial-up beginnings, they have grown into sophisticated operators delivering multi-gigabit speeds and supporting modern digital life. While technology continues to improve access and performance, challenges around equity, competition, and regulation remain critical.

Internet Service Provider - Wikipedia. Retrieved from https://en.wikipedia.org/wiki/Internet_service_provider

What is an ISP? - Cloudflare. Retrieved from https://www.cloudflare.com/learning/network-layer/what-is-an-isp/

History of the Internet - Wikipedia. Retrieved from https://en.wikipedia.org/wiki/History_of_the_Internet

Broadband Technologies - FCC. Retrieved from https://broadbandmap.fcc.gov/

Net Neutrality Resources - EFF. Retrieved from https://www.eff.org/issues/net-neutrality

Information compiled from authoritative sources including Wikipedia, Cloudflare, FCC, industry reports, and networking resources.

Internet Service Provider on Wikipedia: https://en.wikipedia.org/wiki/Internet_service_provider

Cloudflare ISP Learning: https://www.cloudflare.com/learning/network-layer/what-is-an-isp/

FCC Broadband Information: https://www.fcc.gov/consumers/guides/broadband-internet-service

List of ISPs by Country: https://en.wikipedia.org/wiki/List_of_Internet_service_providers