Tier 1 network

Internet Connectivity Distribution & Core

Tier 1 network

A Tier 1 network is a type of Internet Service Provider (ISP) that can reach every other network on the Internet without purchasing IP transit or paying for peering. Tier 1 networks are the backbone of the internet, providing the infrastructure that allows data to travel across the globe.

Characteristics

Tier 1 networks have several defining characteristics:

• They have a global reach, meaning they can connect to any other network on the internet.
• They do not pay for IP transit, as they have settlement-free peering agreements with other Tier 1 networks.
• They own and operate extensive fiber optic networks and other infrastructure.
• They have significant bandwidth capacity and can handle large volumes of internet traffic.

Peering

Peering is a key concept for Tier 1 networks. It involves the exchange of data between two networks without financial settlement. Tier 1 networks engage in settlement-free peering with other Tier 1 networks, which allows them to exchange traffic without incurring costs. This is in contrast to lower-tier ISPs, which often have to pay for IP transit to connect to other networks.

Examples of Tier 1 Networks

Some well-known Tier 1 networks include:

• AT&T
• CenturyLink
• Deutsche Telekom
• NTT Communications
• Sprint Corporation
• Telia Company
• Verizon Communications

Importance

Tier 1 networks are crucial for the functioning of the internet. They provide the backbone infrastructure that supports global data exchange. Without Tier 1 networks, the internet would be fragmented, and data transfer between different regions would be inefficient and costly.

Related Concepts

• Internet backbone
• Internet exchange point
• Network topology
• Autonomous system (Internet)
• Border Gateway Protocol

See Also

• Internet Service Provider
• IP transit
• Peering
• Fiber optic communication
• Bandwidth