Summary

ISP

• Internet Service Provider
• Any home, business or organization that wants to connect to the Internet must use an ISP
• They provide the physical infrastructure (wires, satellites, or cell towers) to connect your home or office to their private network.

Tier 1 ISP Backbone Providers

• National/International coverage (e.g., AT&T, NTT). They own the deep backbone fibers and route traffic globally without paying fees.

Tier-2 National Providers

Note

Regional ISP in Geographic Role Tier-2 ISP in Peering/Transit Role

• Buy bandwidth from Tier-1 and provide service to regions by run Point of Presense (POP) across the counry.
• Purchases IP transit to reach some portion of the Internet from tier-1

Tier-3 Local Providers

• The “last mile” providers that connect directly to your home or business.
• Purchases IP transit to reach Internet from tier-2