Internet

Anmerkungen:

• The most used network in the world. Not one network, but a network of networks: national and state government agencies, non-profit organizations, and for-profit companies. To exchange data, these networks must agree to use Internet protocols.

1. Tier 1 Internet Service Providers (ISPs)

   Anmerkungen:

   • Provide services to their customers and sell access to tier 2 and 3 ISPs
   1. Tier 2 ISPs

      Anmerkungen:

      • Connect with tier 1 ISPs - Provide services to their customers and sell to local ISPs
      1. Tier 3 ISPs

         Anmerkungen:

         • Connect to tier 1 or 2 ISPs - sell access to individuals.
2. Internet Access Points
   1. Network Access Points (NAPs)

      Anmerkungen:

      • Connect tier 1 ISPs together. Sometimes large tier 2 and 3 ISPs also have access directly to NAPs - Only about a dozen NAPs in the U.S. which are run by common carriers such as Sprint and AT&T
      1. Packet Exchange Charges

         Anmerkungen:

         • Peering: ISPs at the same level usually do not charge each other for exchanging messages (Tier 1 to Tier 1 or Tier 2 to Tier 2) Higher level ISPs charge lower level ISPs Tier 3 ISPs charge individuals and corporate users or access
   2. Metropolitan Area Exchange (MAEs)

      Anmerkungen:

      • Connect tier 2 ISPs together
3. Ways to connect to an ISP
   1. Point of Presence (POP)

      Anmerkungen:

      • Used to connect to an ISP, a place at which ISP provides service to its customers.
   2. Cable/DSL

      Anmerkungen:

      • How an individual user connects to an ISP. The userID and password are checked by Remote Access Server
   3. Corporate Users

      Anmerkungen:

      • Access the POP through T1, T3, or ATM OC-3 connections
4. OC 48, OC 192

   Anmerkungen:

   • Backbone circuit for national ISPs, 10 Gbps
5. Internet Access Methods
   1. Broadband

      Anmerkungen:

      • Most methods of accessing the internet are just called "broadband access" Doesn't refer to analog communication, rather it just means high speed
   2. DSL

      Anmerkungen:

      • A point to point technology, designed to provide high speed data transmission over traditional telephone lines.
      1. Asymmetric DSL (ADSL)

         Anmerkungen:

         • The most common type of DSL, uses frequency division multiplexing.
   3. Cable Modems

      Anmerkungen:

      • a type of modem that connects a computer or local network to broadband Internet service through the same cable that supplies cable television service.
      1. Data Over Cable Service Interface Specifications (DOCSIS)

         Anmerkungen:

         • Most common protocol used for cable modems, not a formal standard.
      2. Cable Modem Architecture

         Anmerkungen:

         • Similar to DSL: use shared multipoint circuits instead of point-to-point technology. Equipment: CMTS: Cable Modem Termination System, used for upstream traffic only. - Fiber node with an optical electrical converter. - Combiner (combines Internet traffic with TV video traffic)
   4. Customer Premises Equipment (CPE)

      Anmerkungen:

      • Installed at the customer's location and Contains a line splitter and directs traffic to phone network and DSL modems
   5. Local Loops

      Anmerkungen:

      • Connect to the MDF, MDF splits neighorhood voice and data traffic to phone network and DSLAM (DSL access multiplexer)
      1. Traditional telephone lines (local loop)

         Anmerkungen:

         • Has limited capacity due to telephone and switching equipment at the end offices. constrained by 4 KHz voice channel Much higher bandwidth possible
   6. WiMax

      Anmerkungen:

      • • Wireless standard developed to connect to Ethernet LANs • Can be used as fixed or mobile wireless • Some vendors refer to it as 4G • ISPs are beginning to provide this service
6. Internet Governance

   Anmerkungen:

   • no one organization operates the internet. closest thing: Internet Society (ISOC)
   1. Internet Society (ISOC)

      Anmerkungen:

      • ISOC is an open membership professional society, that works in three areas: public policy, education, standards
      1. IETF

         Anmerkungen:

         • Internet Engineering Task Force: Concerned with evolution of Internet architecture and smooth operation of Internet
      2. IESG

         Anmerkungen:

         • Internet Engineering Steering Group: responsible for management of the standard process. Establishes and administers rules in creating standards.
      3. IAB

         Anmerkungen:

         • Internet Architecture Board, provides strategic architectural oversight, guidance.
      4. IRFT
7. The future of the Internet
   1. NGI

      Anmerkungen:

      • Next Generation Internet funded by NSF, A group called University Corporation for Advanced Internet Development (UCAID) started with 34 universities
   2. ARDNOC

      Anmerkungen:

      • Advanced Research and Development Network Operations Center funded by the Canadian Government, who also developed CA*Net
   3. GIgapops

      Anmerkungen:

      • Similar to NAPs, will provide access to the Internet in the future.