Internet Service Provider

An Internet Service Provider (ISP) is an organization that provide services for accessing internet. It also provide, internet transit, domain name registration, web hosting, usenet service and colocation.

There are three phase in ISP

• Tier 1 ISP :- Tier 1 ISP is an internal provider who exchange internet traffic with tier 1 provider. These ISP exchange traffic strictly through peering agrement without having to pay any fee to anyone. It is backbone of Internet. Tier 1 network is a network that can reach every other network on the internet, in other word they are directly connected to server. They do cabling underwater (called submarine-cable) between countries.

  

  Submarine Cable

  It help to transmit data over the country level. In India there is only one company called TATA Telecom, who do cabling.
• Tier 2 ISP :-  A tier 2 ISP is a service provider who connect between tier 1 and tier 3 internet service provider. Tier 2 provider will exchange internet traffic through peering agrement, as well as purchase internet transit.

  

  Network System

  Tier 2 is over the state level and transmit data from tier one to required states. Tier 2 companies are airtel, jio, bsnl, etc.
• Tier 3 ISP :-  A tier 3 is a provider who strictly purchase internet transit. A tier 3 provider is the last mile provider, who delivers internet access to residential home and businesses ex- our local service provider like airtel ,jio, Vodafone, idea, etc.