McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Chapter 1 Introduction

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction 1.1 PROTOCOLS AND STANDARDS Protocols A protocol is a set of rules that governs data communication. A protocol defines what is communicated, how it is communicated, and when it is communicated. The key elements are syntax, semantics, and timing. –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 and how fast it can be sent. Standards Standards are essential in creating and maintaining an open and competitive market for equipment manufacturers and also in guaranteeing national and international interoperability of data and telecommunications technology and processes.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction 1.2 STANDARDS ORGANIZATIONS Standards are developed through cooperation of standards creation committees. Standard Creation Committees International Standards Organization(ISO), 1947: –The ISO is a multinational body whose membership is drawn mainly from the standards creation committees of various governments throughout the world. –The ISO’s efforts in the field of information technology, which have resulted in the creation of the Open Systems Interconnection(OSI)model for network communications. International Telecommunications Union-Telecommunication Standards Sector(ITU-T).: –By the early 1970s a number of countries were defining national standards for telecommunications. –The United Nations responded by forming, as part of its International Telecommunications Union(ITU), a committee, the Consultative Committee for International Telegraphy and Telephony(CCITT). –On March 1, 1993, the name of this committee was changed to the International Telecommunications Union-Telecommunication Standards Sector(ITU-T).

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction American National Standards Institute(ANSI): –ANSI,s expressed aims include serving as the national coordinating institution for voluntary standardization in the United States, furthering the adoption of standards as a way of advancing the U.S. economy, and ensuring the participation and protection of public interests. Institute of Electrical and Electronics Engineers(IEEE). –It aims to advance theory, creativity, and product quality in the fields of electrical engineering, electronics, and radio as well as in all related branches of engineering. –The IEEE oversees the development and adoption of international standards for computing and communication. Electronic Industries Association(EIA) –The EIA has made significant contributions by defining physical connection interfaces and electronic signaling specifications for data communication.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Forums Frame Relay Forum.: It was formed by Digital Equipment Corporation, Northern Telecom, Cisco, and StaraCom to promote the acceptance and implementation of frame relay. The forum’s results are submitted to the ISO. ATM Forum: The ATM Forum promotes the acceptance and use of Asynchronous Transfer Mode(ATM) technology. The ATM forum is made up of vendors of hardware and software that support ATM. Regulatory Agencies Federal Communications Commission(FCC): The FCC has authority over interstate and international commerce as it relates to communications.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction 1.3 INTERNET STANDARDS There is a strict procedure by which a specification attains Internet standard status. A specification begins as an Internet draft( working document with no official status and a six-month lifetime). 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. Maturity Levels An RFC, during its lifetime, falls into one of six maturity levels: Proposed standard Draft standard Internet standard Historic Experimental Informational.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 1-1 Maturity levels of an RFC

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Proposed standard : A proposed standard is a specification that is stable, well understood, and of sufficient interest to the Internet community. At this level, the specification is usually tested and implemented by several different groups. Draft standard A proposed standard is elevated to draft standard status after at least two successful independent and interoperable implements. Barring difficulties, a draft standard, with modification if specific problems are encountered, normally becomes an Internet standard. Internet standard A draft standard reaches Internet standard status after demonstration of successful implementation. Historic The historic RFCs are significant from a historical perspective. They either have been superseded by later specification or have never passed the necessary maturity levels to become an Internet standard.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Experimental An RFC classified as experimental describes work related to an experimental situation that does not affect the operation of the internet.Such an RFC should not be implemented in any functional Internet service. Informational. An RFC classified as informational contains general, historical, or tutorial information related to the internet. It is usually written by someone in a non- Internet organization, such as a vendor.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 1-2 Requirement levels of an RFC. Requirement Levels RFC’s are classified into five requirement levels: required, recommended, elective, limited use, and not recommended.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Required An RFC is labeled required if it must be implemented by all Internet systems to achieve minimum conformance. ex) IP and ICMP are required protocols. Recommended An RFC is labeled recommended is not required for minimum conformance; it is recommended because of its usefulness. ex) FTP and TELNET are recommended protocols. Elective An RFC is labeled elective is not required and not recommended. However, a system can use it to its own benefit. Limited Use An RFC is labeled limited use should be used only in limited situation. Most of the experimental RFCs fall under this category.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Not Recommended An RFC is labeled not recommended is inappropriate for general use. Normally a historic (obsolete) RFC may fall under this category.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 1-3 Internet administration 1.4 INTERNET ADMINISTRATION

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Internet Society(ISOC) The Internet Society(ISOC) is an international, nonprofit organization formed in 1992 to provide support for Internet standards process. Internet Architecture Board(IAB). The IAB is the technical advisor to the ISOC.. The IAB are to oversee the continuing development of the TCP/IP Protocol Suite and to serve in a technical advisory capacity to research members of the Internet community.. The IAB is the editorial management of the RFCs Internet Engineering Task Force(IETF). The IETF is a forum of working groups managed by the Internet Engineering Steering Group(IESG). IETF develops and reviews specification intended as Internet standards.. The working groups are collected into areas, and each area concentrates on a specific topic. (Applications / Internet protocols/ Routing/ Operations/ Use services/ Network management/ Transfer/ Internet protocol next generation(IPng)/ Security.)

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction Internet Research Task Force(IRTF) The IRTF is a forum of working groups managed by the Internet Research Steering Group(IRSG). IRTF focuses on long-term research topics related to Internet protocols, applications, architecture, and technology. Internet Assigned Numbers Authority(IANA)and Internet Corporation for Assigned Names and Numbers(ICANN) The IANA was responsible for the management of Internet domain names and address until October At that time the ICANN, a private, nonprofit corporation managed by an international board, assumed IANA operations. Network Informational Center(NIC) The NIC is a responsible for collecting and distributing information about TCP/IP protocols.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Introduction 1.5 A BRIEF HISTORY Four-node ARPANET established ARPA hosts implement NCP Development of TCP/IP suite begins An internet tested using TCP/IP UNIX distributed to academic/research sites CSNET established TCP/IP becomes the official protocol for ARPANET MILNET was born NSFNET established ARPANET decommissioned and replace by NSFNET NSFNET goes back to being a research network.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2000 Figure 1-4 The Internet.