Study Unit 13 Flashcards
Distributed processing
decentralized processing tasks and data storage and assigning functions to multiple computers, in separate locations
-allows reductions in amnt of comm traffic b/c data needed locally could reside locally
LAN
need to increase productivity lead to LAN development
LAN-interconnection bet devices in a single office or bldg
Client server model
most cost effective and easy to admn arrangement for LANs
-differ from peer to peer ntwk in that devices play more specialized roles; client processes request svc from server processes
client server arrangement
server centrally located and devoted to fx needed by all ntwk users
-ex (mail servers, app servers)
determination as server by function it performs (simple personal computer can be a server)
Client
any object that uses resources of another object; client can be either device or sftwr program
client-device that requests svcs from a server
client device-displays user interface and enable data entry, queries, and receipts of reports
Key to client-server model
runs processes on platform most appropriate to process while attempting to minimize traffic over the ntwk (3 tiered architecture of client, app, db)
client svr systems made from eqt from multi vendors
security for client-svr systems more difficult than in highly centralized system b/c of access pts
Security risks of decentralization
unauthorized sftwr easily installed on ntwk; exposure to virus and liability to copyright violation
important files stored on local comp not backed up properly
app written by users of local comp not adhere to stds of org, making data sharing difficult
Classifying Networks by Geographical extent and fx
-LAN
connects devices w/in single office/home or bldgs.
owned by a single org
WAN
wide area ntwk- consists of conglomerate of LANs over widely separated locations; key is either public or privately owned
advantage-spread cost of ownership among multiple org
simplest config is 1 PC using dial up to connect to ISP
Publicly owned WAN
available to any user w/ a compatible device (phone, internet)
assets paid for by means other than indiv imposed user fees
quality can’t be guaranteed, security is highly questionable
Privately owned WAN
profit making
offer faster, secure data comm svc to orgs that don’t make investment in the infrastructure
Types of private WANs
- VANs- private ntwk provide customers w/ reliable, high speed secure transmission of data
- -add value, give cust error detection/correction, e-mail for EDI
VPN - virtual private ntwk
- cheap way to solve problem of high cost of leased lines
- -company connects each office to local ISP, routes data thru public internet
- -VPN success depends on encryption in transit
Intranet vs extranet
both types of WANs (wide area ntwk)
intranet- share info thru org by internet and web sftwr to internal ntwk
extranet- linked intranets of 2 or more orgs (supplier and customers)
-uses public net to transmit, req pword for access
TCP/IP
Transmission Control Protocal/ Internet Protocol
suite of comm protocols (rules/stds) used to connect computers to internet; built into ntwk op systems
HTML
hypertext markup lang
allows users to click on a word/phrase (hyperlink) on screens and have another doc automatically be displayed
HTTP
allows hyperlinking across internet not just single computer
browser allows users to read html from computer (web)