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E-Commerce Notes #12



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  • UDP - User datagram protocol (most used protocol). www is based on this protocol.
  • Network Interface Layer is a club of physical layer and protocol of data packet flow.
  • DHCP - Dynamic Host Controller Protocol, provides dynamic IP address to the once requesting for it.
  • ICNM - Governs the IP address.
  • Routers - Helps packets to reach the destination (in local level), bridges (in regional), gateways (in national level )
  • Transport Layer decides the how they are going to flow, like session, security, and data path.
  • Application Layer is which has the interface with the user, which arranges the data packets in the correct order.


Important topics :
  • Layers of TCP/IP

  • Their functionality
  • Benefits of using TCP/IP

  • Definition of IP address, Domain name, DNS, route servers - are the central directories that list all the domain names that are currently in use. The DNS server consults the route server in case it is not able to find the destination - Domain name.

  • Governing bodies of internet are :
    • IAB - Internet Architecture Board - Defines the overall structure of internet.
    • ICANN - Internet Corporation for Assigned Names and Numbers - Assigns IP addresses
    • IESG - Internet Engineering Steering Group - Looks over the standard settings
    • IETF - Internet Engineering Task Force - Forecasts the next step in the growth of internet
    • ISOC - Internet Society - Consortium of govt. agencies, non-profit organizations and corporates that monitor the internet policies and practices.
    • W3C - World Wide Web Consortium - Finalizes the language standards.

  • Important Internet protocols
    • HTTP - Hyper text Transfer Protocol
    • SMTP - Simple Mail Transfer Protocol
    • IMAP - Instant Message Access Protocol
    • POP - Post Office Protocol
    • FTP - File Transfer Protocol
    • SSL - Secure Socket Layer
    • Telnet - A terminal emulation program that runs in TCP/IP. One can run the telnet from the client machine and emulate another system
    • PING - Packet Internet Grouper - Check the connectivity between a host and client.
    • FINGER - Helps to who is logged, how long are they connected.

  • Intranets and Extranet - Intranet is a TCP/IP network located within a single organization for the purpose of the communication and information processing. Unlike intranet, in extranet a firm provides outsiders permission to access the internal network
  • NSPs - Network Service Providers are one of the hubs which own and control one of the major networks which form the backbone of the internet. The backbone is like a pipeline that transfers data through out the world in milliseconds The bandwidth measures how much data can be transferred throughout the network in a fixed amount of time.
  • NAP - Network Access Points - These are the hubs where the backbone intersects the regional and the local network
  • MAE - Metro Area Exchange - These are the hubs where the backbone intersects the regional with // Check this : other regional networks
  • RH - Regional Host



Internet can also be characterized by hourglass modulus structure having four layers with the lower layer containing bit carrying infrastructure including cables and switches and upper layer containing the user applications such as e-mails and web. The narrow vast are the transportation protocols such as TCP/IP. The four layers are :

  • Network Technology substrate
  • Transport services and the representation standards
  • Middleware services
  • Applications

WWW is one of the service internet. We require internet connection and technologies. Markup language is used to present information online.

First markup language is SGML - Standardized Generalized Markup Language.
HTML - HyperText Markup Language
XML - eXtensible Markup Language

Web server plays active role, when the client requests for dynamic  web pages

Hyperlink is the most important component of web.

Applications of web :
  • E-mail
  • Search Engine
  • Intelligent Bots - Software programs that gather or filter information and provide it to the user. e.g. - shopping bot.
  • Instant Messaging / Chat
  • Music / Video transmission
  • VoIP
  • WAP - Wireless Access Protocol (Language WML - Wireless Markup Language)

Limitations of Internet I
Attenuation
Bandwidth Limitation
Quality of service limitation
Network Architecture limitation
Language development limitation

GPRS - General Packet Radio Switching



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