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