Network Applications

Network Applications ™   Marketing and Sales o    Marketing    Collect, exchange and analyze data relating to the customers needs    Product development cycles o    Sales    Tele shopping,    On line reservation systems ™   Financial Services o    Online Banking o    Foreign Exchange Transfers o    Rates ™   Manufacturing Computer Aided Design o    Computer Assisted Manufacturing o    Network Applications ™   Electronic Messaging ™   Teleconferencing o    Conferences to occur w/o participants at the same place o    Chat o    Voice Conferencing o    Video Conferencing ™   Cable Television

Network Criteria

Network Criteria

™   Performance Performance can be measured in many ways including Transit and Response Time o    Depends on a no. of Factors:    Number of USERS    Type of Transmission Medium    Hardware    Software    Network Criteria    Number of USERS    Large Number of concurrent users slow network    Design of a network    Peak Load Periods    Network Criteria    Type of Transmission Medium    Medium defines speed at which data can travel    Fiber Optic Cable    100Mbps and 10 Mbps    Hardware    Software    Hardware    Effect speed and the capacity of transmission    Fast computer with large storage capacity    Software    Network Criteria                     Software                                     Software    processes    data    at    sender    ,                                                   receiver and intermediate nodes                                    All communication steps need software:                                   Moving message from node to node                                   Transforming,  Processing at the sender and receiver                                   Error Free Delivery Well designed software can speed up the process ™   Reliability o    Depends on a no. of Factors:    Frequency of Failure    Recovery Time of a Network after Failure   Catastrophe    Fire , Earthquake or Theft ™   Security o    Unauthorized Access   Sensitive data   Protection at multiple levels:   Lower level: Passwords and user ID codes   Upper Level: Encryption o    Viruses

Advantages of Distributed Processing

Advantages of Distributed Processing ™   Security A system designer can limit the kind of interaction that a given user can have with the entire system. 9   For example :  Bank's ATM ™   Distributed Data bases No one system need to provide storage capacity for the entire database    For  example  WWW  gives  user  access  to  pages  stored  anywhere  on Internet ™   Faster Problem Solving Multiple  computers  working  on  a  problem  can  solve  a  problem  faster  than  a computer working alone ™   Security through Redundancy Multiple    computers    running    the    same    program   provide    security   through redundancy If one computer hardware breaks down then others cover up. ™   Collaborative Processing Both multiple computers and multiple users can interact for a task

Key Data Communication Terminology

KEY DATA COMMUNICATION TERMINOLOGY ™   Link: connects adjacent nodes Wires, Cables, Any thing that physically connects two nodes ™   Path: end-to-end route within a network ™   Circuit: the conduit over which data travels ™   Packetizing: dividing messages into fixed-length packets prior to transmission over a network's communication media ™   Routing: determining a message's path from sending to receiving nodes 9   The  transmission  medium  may  itself  be  a  network,  so  route  needs  to be specified Network "A NETWORK is a set of devices (Nodes) connected by Communication Links" ™   Node:  Can  be  a  Computer,  Printer  or  any  other  device  capable  of  sending  or receiving    The links connecting Nodes are called COMMUNICATION CHANNELS Networks- Why we need them? Networks- Why we need them? It is often impractical for devices to be directly connected for two major reasons: o    The  devices  are  very  far  apart.  They  are  expensive  to  connect  just  two  devices with one in Lahore and other in Islamabad o    Large   set   of   devices   would   need   impractical   number   of   connections   e   .g. Telephone   Lines   in   the   world   and   all   the   computers   owned   by   a   single organization Solution to the Problem=Networks o    Solution is to connect all devices to a central system known as a NETWORK in which all terminals or computers share the links. o    Two Main Classifications of the Networks LANS WANS DISTRIBUTED PROCESSING Instead  of  a  single  large  machine  being  responsible  for  all  aspects  of  a  process  , each separate computer handles a subset of the task    Example - Office Work