Tier 1 Internet Service Provider (Tier 1 ISP)

A Tier 1 ISP or a Tier 1 Internet Service Provider is able to establish a direct connection with global Internet backbone. The access to the Internet backbone is limited to a defined region and facilitates a voluntary exchange of information within networks. A Tier 1 Internet Service Provider belongs to the most superior class of ISPs and has the ability of maintaining region's entire routing table. With facility of its own IP network, a Tier 1 ISP connects with the primary Internet backbone or other peers in different regions.

Internet Service Providers belonging to Tier 2 and Tier 3 categories, buy bandwidth from Tier 1 Internet Service Provider to facilitate Internet connectivity to individual users. It should be noted that a Tier 1 ISP is not supposed to charge for any exchange of information and traffic with other peers in different regions. Payment of peering fees or transit charges disqualifies an ISP as a Tier 1 ISP. The description of Tiers in case of Internet Service Providers is based on a common understanding and is not governed by any international authority. It is very difficult for an Internet Service Provider to act as a Tier 1 ISP by stringently adhering to the described norms.

Usually large telecommunication providers exchange or buy resources of fiber among each other instead of actual exchange of any monetary settlements. The arrangement of peering is established to acquire equality among Tier 1 Internet Service Providers of different regions and to have a common basis of understanding. In terms of ethics of peering policies, a Tier 1 Internet Service Provider is not open to new peering association and is supposed to maintain the current peering relation with all important regional networks pertaining to a particular region. The Internet community recognizes many Tier 1 ISPs such as Orange, AT&T, GTT, Cogent Communications and so forth.

The Three Tiers of ISP

An internet service provider (ISP) is a company that provides internet connection to the end-users. There are three levels of ISPs namely tier-1, tier-2, and tier-3. So, what are the features of each tier and how do these tiers differ from each other? Let us find out.

Tier-1 ISPs: These ISPs are at the top of the ISP hierarchy. As they have a global reach, they do not need to pay for internet traffic passing through their network unlike their lower-tier counterparts that are required to pay a fee for passing traffic from one location to another. They typically connect with other ISPs in the same tier and allow free traffic passes to one another. This helps them save costs. They build and own enough network infrastructure to provide traffic to other ISPs, but not necessarily to end-users.
Renowned tier-1 internet providers include AT&T, Sprint, CenturyLink and Verizon.

Tier-2 ISPs: This tier of internet service providers forms a link between tier-1 and tier-3 ISPs. They peer with the other tier-2 networks and are required to buy access to larger tier-1 networks. Unlike tier-1 players that have global reach, these have regional or country reach. The name �tier-2� does not mean that their service is inferior to that of tier-1. As a matter of fact, most of the tier-1 ISPs prefer dealing with large clients, leaving tier-2 players to focus on regional customers. Popular tier-2 networks include Comcast, Virgin Media and Vodafone.

Tier-3 ISPs: These ISPs are the closest to the end-users and offer last-mile connectivity. They help the end-users connect to the internet when they don�t have a network of their own, offering the connection leading into their home or office. They are required to pay some amount to tier-2 networks depending on the traffic their network generates. Popular tier-3 network providers include Comcast, Verizon Communications, and Deutsche Telekom.