The Internet

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• WAN interface of SOHO router connects to the internet

The Public Switched Telephone Network (PSTN)

• most SOHO subscriber internet access use DSL, cable, fiber optics, cellular, and satellite services
  • some legacy systems use public switched telephone system (PSTN)
• SOHO router is described as customer premises equipment (CPE)
  • this is any terminal and routing equipment placed at the customer site
  • may be owned or leased from the telecommunications company (telco)
  • CPE is connected via its modem and WAN port to the local loop
    • cabling from customer’s premises to the local exchange
  • point where telco’s cabling enters the customer premises is referred to as the demarcation point (demarc)

Internet Service Providers (ISP)

• major infrastructure of the internet consists of high-bandwidth trunks connecting Internet Exchange Points (IXPs)
• within an IXP datacenter, ISPs establish links between their networks
  • use transit and peering arrangements to carry traffic to and from parts of Internet they don’t own
• is a tiered hierarchy of ISPs that reflect the extent they depend on transit arrangements with other ISPs

Internet Standards

• several organizations are responsible for the development of the Internet
  • Internet Assigned Numbers Authority (IANA)
  • Internet Engineering Task Force (IETF)