Hilbert Pastrana
Instructor: Mr.Dennis Pua
BASICONT
Basic Principles of Networking
· NNetworking – problem of delivering a message from a source to destination.
· Tthe problem of giving meaning to these messages received is called communication.
USE OF COMPUTER NETWORKS
· NNetwork for companies
Ø Resource sharing
Ø Dynamic rerouting
· NNetworks for people
Ø Access to remote information
Ø Person-to-person communication
Ø Interactive communication
Communication channels – a pathway over which information can be transferred.
· CComplex channel - is a channel whose whose direction of transmission is unchanging
· HHalf-duplex channel – a channel in which the direction may be reversed, but the transmission does not occur at the same time.
· FFull-duplex channel – channel that allows simultaneous exchange in both directions.
Types of Transmission Technologies
· Point to point network – consist of many connections to individual pairs of machines.
· Broadcast networks – all the machines on the network share a single channel.
Types of Network Topologies
· BBus Network - common channel connects all devices.
· RRing network – all messages travel in a ring, either in clockwise or counterclockwise direction.
· TTree network – integrates multiple star topologies into a bus.
· SStar network - a central connection point called the (HUB) is used and all devices connect through it.
· MMesh network – involves the concept of routes, where a message is sent on the network can take any several possible paths from the source to destination.
DISTRIBUTED SYSTEMS
ü ((CDP) Centralized data Processing: the conventional way of doing all the processing & control on centralized computers.
ü ((DDP) Distributed Data Processing: manipulation of data using distributed system.
ü Client/Server: extension of distributed data processing wherein it provides the best of both centralized & distributed data processing.
ü Local Area Network (LANs): connect network devices over relatively short distances.
Information System - particular discipline or branch of learning that is concerned with the application of information to organizational needs.
Information - measures of quantity of data in message(information theory contest) any data that is relevant to has some value (information system concept
Data - any sign , symbol or measure, which is an form that can be directly captured by a computer or machine.
Capabilities of Information Technology
- Input
- Processing
- Storage
- Output
Applications:
- Medical diagnosis
- Chemical analysis
- Genetics
- Geology
- Computer Fault diagnosis
- VLSI design
- Software development and debugging
- Configuring computer system
- Financial analysis
- Education
Database Management System (DBMS)- collection of computer programs that allow users to store modify and extract information from database.
Database-a systematic collection of related information organized in such a way that a computer program can quickly select desired pieces of informaation.
Field- a single piece of information
Record- one complete set of fields
File- a collection of records
Query Language- is a specialized language that allows users to request information from the database.
SEQUEL (Structured English Query Language)
Benifits of DMBS
- Customer details database
- Business sales database
- Searchable database
- Confidential information database
- Based on a relational model developed by E.F Codd
- Data and relations are organized in tables
- A table is collection of records and each record in a table contains the same field.
- Certain fields maybe designated as keys, such that when searching for a particular field, the keys will serve as indices to speed up the search
- atomicity
- consistency
- isolation
- durability
in a useful and navigable format.
Decision Support System (DIS)-interactive computer based system for informing and supporting makers.
Brief History
1962-The internet was first conceived in the early 60's under the leadership of the US Department of Defense's Advance Reasearch Project Agency (ARPA)
1965-Work on ARPANET begins.
1967-Delegates at symposium for the Association for Computing Machinery in Gatlingberg, Tennessee, discuss the first plans for ARPANET.
1968-First generation of networking hardware and software design.
1969-ARPANET connects Stanford Research Institute, UCLA, UC Santa Barbara and the University of Utah.
1970-ALOHANET developed at the University of Hawaii.
1972-The InterNetworking Working Group becomes the first of several standards-setting entities to govern the growing network. Vinton Cerf is elected the first chairman of the INWIG, and later becomes known as the "Father of the Internet"
1973-The ARPANET goes international.
1974-Bolt, Beranek & Newman opens Telnet, the first commercial version of the ARPANET.
1976-Queen Elizabeth goes online with the first royal email messages.
1978-TCP checksum design finalized.
1979-USENET newsgroup established to talk about the net, politics, religion and other topics/
1982-The term "internet" is used for the first time.
1983-TCP/IP becomes the universal language of the internet. Internet as we know it today is born.
1988-Internet worm unleashed. The Computer Emergency Response Team (CERT) was formed to address security concerns raised by the worm.
1990-The ARPANET was decommissioned, leaving only the vast network-of-networks called the Internet.
1991-The World Wide Web is born!
1993-Mosaic, the first graphics-based Web browser, becomes available.
1996-The internet covers the globe. The Age of the Internet has arrived.
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