CS99I Meeting 1 Notes

Updated by Gio Wiederhold, 20 Jan 2001.

Topics Covered briefly

Course Goals

Discussion; understanding what's going on; not telling what the future will bring.

Student participation: reading, arguing, writing. Freshies only

Technology Origin:

Resource sharing for ARPA (the Defense Department/s Advanced Research Projects Agency) Contractors.
Objectives:
  1. Remote use of computers: TELNET protocol
  2. File transfer for remote execution: FTP protocol
  3. Robustness: redundant linking
  4. Limited loss on failure, load balancing: packeting of messages
Reading: CS99 chapter about the Internet.

Technologies

Multiple levels of providers:

  1. Local servers for LANs
  2. Local Internet service providers
  3. Regional Internet services (BART, Los Nettos, (what was yours in your home town?)
  4. Backbone linkages -- wide, trancontinental links (leased from the phone companies, as MCI etc.)

Cable transmission versus Plain-old-telephone-service (POTS)
    Bandwidth usage for messages, images, TV

Transmission Control Protocol: TCP, specifies

    Packets with headers: from, to, number
    Nodes with forwarding information tables
    Later: four level adresses: 171.64.64.64. (what is yours?)
    Three level addresses: cs.stanford.edu, translated by domain name servers (DSN)
Later a simplified protocol for email: SMTP
Internet protocol (IP), provided for interconnection of local subnetworks networks (LAN>, connected by Internetwork routers.
LANs often use the Ethernet protocol local wire networks with
    Carrier Sense Multiple Access (CSMA) and
    Collision detection (CD) and
    exponential backoff
developed origunally for satelite networks (Aloha net in Hawaii).

The ethernet protocol is a broadcast protocol, versus a point-topoint protocol. Thet protocols differ in terms of

  1. Security
  2. Cost reimbursement. Alternatives are:
    1. Receiver pays: Voluntary subscription. Example: Public TV - PBS.
    2. Receiver pays: Required subscription, controlled access. Example: Stanford SITN.
    3. Receiver pays: Government levies taxes or fees. Example: British, Dutch TV.
    4. Sender pays: Corporate or organizational support. Example: churches.
    5. Sender pays: Government supports sender. Example: Voice of America.
    6. Sender pays: Commercial tax on sales. Example:.
    7. Sender pays: Advertising. Example:.
    8. Manufacturer of receiving equipment is taxed: Example: attempted with VCRs, as in ( France).
    9. Manufacturer of receiving supplies: Example: DAT tapes.
    10. others?
    And combinations of these methods.
Their effectiveness differs in media, settings [ref World-wide Wireless magazine ~1910] (social, ubiquity, ...).

Who should get paid: the broadcast service, the contents supplier, ... ? [Napster]. More discussion needed.

Limiting Broadcast Access

Protecting minors versus First-amendment rights. See COPA (Child Online Protection Act ) Commission material.

Distributed, autonomous development

Requests for comments (RFCs) to proposals, collected at SRI International. Implemented and adopted by the community, after discussion, when effective.
Alternate means of developing standards
    Implement, show, convince others of usefullness and leverage
    Committee of wise men, government mandates
    Commercial value of getting one's standard accepted
    Surfeit of standards, confusion, cost, dirty tricks.

Binary Number representation

Counting with only two symbols {0, 1} . (need a reference to reading?).
more in next set of notes

Notes

See class chapter about the Internet and the glossary.