et3003-1 introduction (semester ii 2013-2014)

IntroductionComputer Networks

Tutun JuhanaTelecommunication EngineeringSchool of Electrical Engineering & InformaticsInstitut Teknologi Bandung

1

Reference

• TCP/IP Protocol Suite, Fourth Edition, Behrouz A. Forouzan, McGraw-Hill

The Menu

• Theories• Hands-on

A Brief History

• A network is a group of connected, communicating devices such as computers and printers

• An internet is two or more networks that can communicate with each other

• The most notable internet is called the Internet

internetsociety.org

Internet today

http://scoop.intel.com/what-happens-in-an-internet-minute/

PROTOCOLS AND STANDARDS

Protocol

• A protocol is a set of rules that governs communication

http://www.teracomtraining.com/online-courses-certification/samples/lesson1104-protocols-and-standards.htm

• For communication to occur among entities, they must agree on a protocol

We agree to talk inEnglish…

• In computer networks, communication occurs between entities in different systems

• The key elements of a protocol– Syntax– Semantics– Timing

A protocol defines what is communicated, how it is communicated, and when it is communicated

Syntax• Syntax refers to the structure or format of

the data, meaning the order in which they are presented

Semantics• Semantics refers to the meaning of each

section of bits

Timing• Timing refers to two characteristics

– When data should be sent – How fast it can be sent

http://dev.opera.com/articles/view/http-basic-introduction/

Standards• Standards are essential in

– creating and maintaining an open and competitive market for equipment manufacturers

– guaranteeing national and international interoperability of data and telecommunications technology and processes

• Standards provide guidelines to manufacturers, vendors, government agencies, and other service providers to ensure the kind of interconnectivity necessary in today’s marketplace and in international communications

• De facto standard ( “by fact” or “by convention”)– Standards that have not been approved by an

organized body but have been adopted as standards through widespread use are de facto standards

– Examples of de facto standards are MS Office and various DVD standards

• De jure standards ( “by law” or “by regulation”)– Standards that have been legislated by an

officially recognized body

STANDARDS ORGANIZATIONS

Standards Creation Committees

Forum

To accommodate the need for working models and agreements and to facilitate the standardization process, many special-interest groups have developed forums made up of representatives from interested corporations

Regulatory Agencies

INTERNET STANDARDS

• An Internet standard is a thoroughly tested specification that is useful to and adhered to by those who work with the Internet

• It is a formalized regulation that must be followed

• There is a strict procedure by which a specification attains Internet standard status

• A specification begins as an Internet draft• Upon recommendation from the Internet

authorities, a draft may be published as a Request for Comment (RFC)

• Each RFC is edited, assigned a number, and made available to all interested parties

• RFCs can be found at http://www.rfc-editor.org

Maturity Levels of RFC

RFC Requirement Levels

INTERNET ADMINISTRATION

ietf.org

• Internet Assigned Numbers Authority (IANA) and Internet Corporation for Assigned Names and Numbers (ICANN)– IANA, supported by the U.S. government, was

responsible for the management of Internet domain names and addresses until October 1998

– ICANN, a private nonprofit corporation managed by an international board, assumed IANA operations

• Network Information Center (NIC)– Responsible for collecting and distributing information

about TCP/IP protocols