Question

What is the basic structure of the Internet? What is an IXP? What is the difference between a Tier 1 ISP and a tier 3 ISP? Briefly explain peering and transit connections and the difference between them.

Answer 1

The basic structure of internet is ir is a hierarchical structure.

It consists of 3 tiers which is a tier1, tier2 and a tier3.

Tier1 ISP: These are the backbone providers which connect straight with the internet. Free access of passage from within the traffic to be given.Some of the tier 1 service providers are AT&T, British Telecom, InfoNet, MCI etc.

Tier3 ISP: These are the smallest among all the levels of ISPs which help to supply the internet connectivity to home or small organizations. So as to have a global connectivity they collaborate with tier1 or tier2.

Some of the examples are: Google Fiber, Cable Verizon etc

Tier 1 would have service level agreements without the tier 1 internet traffic cannot be exchanged among the countries or continents. The tier 2 connects the tier 1 and tier 3, which helps to exchange the traffic through peering and tier 3 is considered as the last mile provider.