What is an ISP?
An ISP (internet service provider) is a company that provides individuals and organizations with access to the Internet and related services. An ISP has the equipment and telecommunication line access required to have a point of presence on the Internet for the geographic area served.
ISPs allow customers to access the internet while providing additional services such as email, domain registration, and web hosting. ISPs may also offer internet connection types, such as cable and fiber. Connections can also come in the form of high-speed broadband or non-broadband. The Federal Communications Commission (FCC) states that to be considered high-speed, a connection must have download speeds of at least 25 megabits per second (Mbps) and upload speeds of a minimum of 3 Mbps.
An ISP is also sometimes referred to as an internet access provider. ISP is also sometimes used as an abbreviation for independent service provider to distinguish a service provider that is a separate company from a telephone company.
How do ISPs work?
ISPs are connected to one or more high-speed internet lines. Larger ISPs have their own high-speed leased lines, so they are less dependent on telecommunications services and can provide better customer service.
ISPs also keep thousands of servers in data centers—the number of servers depends on their internet service area. These large data centers manage all customer traffic. Multiple ISPs are also connected to large backbone routing centers.
ISPs are grouped into the following three tiers:
- Tier 1 ISPs. These ISPs have the most global reach and own enough physical network lines to carry most traffic. They also negotiate with other tier 1 networks to allow free traffic to pass through to other tier 1 providers. Tier 1 ISPs typically sell network access to tier 2 ISPs.
- Tier 2 ISPs. These ISPs have regional or national reach and are service providers that connect tier 1 and tier 3 ISPs. They must purchase access to larger tier 1 networks but are peers with other tier 2 ISPs. Tier 2 networks focus on consumer and commercial customers.
- Tier 3 ISPs. These ISPs connect customers to the internet using another ISP’s network. Tier 3 ISPs use and pay higher-tier ISPs for access to internet services. They focus on providing internet access to local businesses and consumer markets.
ISPs and the different types of services
ISPs provide the following internet services:
- Cable. This service uses coaxial cable, which delivers TV. Cable internet has low latency, which is good for users who need less delay or lag time. The cable has a download speed of 10 to 500 Mbps and an upload speed of 5 to 50 Mbps.
- Fiber: The Internet uses fiber optic cable to transmit data and provides much faster speeds than cable or digital subscriber lines (DSL). Fiber has download speeds of 250 to 1,000 Mbps and upload speeds of 250 to 1,000 Mbps. It is suitable for online gamers and other heavy internet users.
- DSL. DSL connects users to the internet using a telephone line. It is widely available but slowly replaced by more reliable broadband connections such as cable and fiber. DSL is slower and offers download speeds of 5 to 35 Mbps and upload speeds of 1 to 10 Mbps. It is a good option for users in rural areas and those who mainly surf the web or stream TV on only one device.
- Satellite. Satellite internet access works through the use of communication satellites. Ground stations relay internet data as radio waves to and from satellites, likely in low Earth orbit and farther ground stations. Satellite is slower, with download speeds of 12 to 100 Mbps and upload speeds of 3 Mbps, but it is a good option for users in remote areas.
Most ISPs offer a combination of these services.
What are examples of ISPs?
According to independent research by BroadbandNow and data from the FCC, more than 2,900 ISPs in the U.S. These ISPs offer various services. The top five ISPs covered by the estimated population include HughesNet, Viasat Internet, AT&T Wireless, Verizon, and T-Mobile.
To break this down based on the tiers examined above, tier 1 ISPs include the following U.S.-based companies:
- AT&T
- CenturyLink
- Sprint
- Verizon
Tier 2 ISPs include the following companies:
- Comcast
- Cox Communications
- CTS Telecom
Tier 3 ISPs include smaller regional and local providers.
How to choose an ISP
Users should choose an ISP based on several factors, including the following:
- Coverage area. Which providers offer service to the user’s region? There may be limited options if the user lives in a rural area.
- Types of services offered. In addition to cable, fiber, DSL, or satellite, does the ISP provide online security? Free email access? Website hosting? What about mesh Wi-Fi? Be sure the ISP’s offerings match the user’s needs.
- Download and upload speeds. Will the user be gaming online or working from home and using video teleconferencing? Both require different levels of service. For example, at least 25 Mbps bandwidth is needed to stream 4K video.
- Pricing. Does the ISP bundle services such as internet, phone, and TV, and if so, does combining services save money? Are there any data caps? What about equipment costs? Is there a contract?
- Consumer satisfaction rating. Check unbiased sources for provider ratings.
ISPs may throttle or slow down a user’s internet speed to regulate traffic and clear up network congestion. They may also throttle a user’s internet speed when they reach a specific data limit. However, throttling violates net neutrality, the prevailing idea that ISPs should treat all communications over the Internet equally.
For example, ISPs can choose to throttle specific websites that users visit simply because they use much data. In the past, ISPs throttled their customers’ internet connection when they connected to Netflix, meaning the user experience on Netflix’s platform was diminished due to the ISP.