Internet (Class 7)

Local Area Network (LAN)

A telecommunications network that connects several IT components together within a small, usually privately owned area

Backbone Network

A network of LANs, usually limited to a single campus or building

Metropolitan Area Network (MAN)

Network of LANs and/or Backbones, limited to a single metropolitan area

Wide Area Network (WAN)

A network of MANs and/or Backbones distinguished by no geographical boundaries

Internet is...

a network of networks. Like the universe with many independent systems linked linked together

Architecture of internet

ISPs are autonomous systems and share routing info using Border Gateway protocol (BGP)

Peering

ISPs at the same tier typically do not charge each other

ISPs Service charges

Higher-tier ISPs charge lower-tier ISPs for data transfer

Internet Service Provider (ISP)

a company that provides access to the internet for a monthly fee

Tiers of ISPs

Tier 1 ISP: National ISP

Tier 2 ISP: Regional ISP

Tier 3 ISP: Local ISP

Internet Exchange point (IXP)

data exchange

What do Tier 2 ISPs rely on to transmit messages to ISPs in other countries?

Tier 1 ISPs

Who do Tier 2 ISPs provide services to?

Their customers and local ISPs

What is an example of a local ISP that Tier 2 ISPs sell internet access to?

Comcast or Xfinity