정보통신 CST313 Int. to Data Communications and Networking Behrouz FOROUZAN 조 충 호 고려대학교 전산학과

수업계획 교과목명 : 정보 통신 학수번호 : CST313 학점 및 이수구분 : 3학점, 전공필수 주당시간 : 강의(3시간) 수강대상 : 전산학과 3학년 담당교수 : 조충호 연 구 실 : 9-210호 전화번호 : 1345,1778(조교) email : chcho@tiger.korea.ac.kr

수업목표 데이터 통신과 컴퓨터 통신에 대한 기본 원리 및 구조, 표준안, 그리고 관련 기술과 개념들을 이해한다.

수업 방법 지난 수업 내용을 정리하고 추가 질문을 받는다. 수업 내용을 제시하고, 수업을 진행한다. 강의 내용에 대한 요점을 정리한다.

평가방법 평가기준 :상대평가 중간고사 : 30% 기말고사 : 30% 과제물 : 30% 출석 : 10%

교재명 및 참고문헌 Behrouz Forouzan, “Introduction to Data Communication and Networking”, McGraw-Hill, 1998 김종상 역, “데이터 통신과 컴퓨터 통신”, 희중당, 1995 성승희, 이인행, “데이터 통신과 프로토콜”, 홍릉과학출판사, 1991 안병호, 박정훈, “데이터 통신론”, 이한출판사, 1996 채기준, 김준년, “데이터 통신 및 분산망”, 희중당, 1995

목차 1. Introduction 2. Basic Concepts 3. OSI Model 4. Signals 5. Encoding 6. Transmission of Digital Data Interfaces and Modems 7. Transmission Media 8. Multiplexing

목차(cont’d) 9. Error Detecting and Correction 10. Data Link Control 11. Data Link Protocol 12. Local Area Networks 13. Metropolitan Area Networks 14. Switching A Network Layer Function 15. ISDN 16. X.25

목차(cont’d) 17. Frame Relay 18. ATM 19. SONET/SDH 20. Networking and Internetworking Devices 21. Transport Layer 22. Upper OSI Layer 23. TCP/IP

1장 개요 1.1 데이터 통신 1.2 네트워크 1.3 프로토콜과 표준안 1.4 요약

1.1 데이터 통신 ~ is the process of communicating information in binary form between two or more points. ~ is the exchange of data(in the form of 0s and 1s) between two devices via some from of transmission medium(such as a wire cable)

기본 특성 The effectiveness of a data communication system depend on three fundamental characteristics 전달(Delivery) ~ must deliver data to the correct destination(the intended device or user) 정확성(Accuracy) ~ must deliver data accurately 적시성(Timeliness) ~ must deliver data in a timely manner

구성 요소 step 1: step 2: step 3: ……. 송신자 수신자 전송매체 프로토콜 메시지

구성 요소(cont’d) 메시지(Message) 송신자(Sender) 수신자(Receiver) ~ is the information(data) to be communicated. (text, numbers, pictures, sound, video or any combination of these) 송신자(Sender) ~ is the device that sends the data message. (computer, workstation, telephone handset, video camera) 수신자(Receiver) ~ is the device that receives the message.

구성 요소(cont’d) 전송매체(Medium) 프로토콜(Protocol) ~ is the physically path by which a message travels from sender to receiver. (twisted pair wire, coaxial cable, fiber-optic cable, laser , or radio waves(terrestrial or satellite microwave)) 프로토콜(Protocol) ~ is a set of rules that govern data communication.

1.2 네트워크(Networks) ~ is a set of devices(node) connected by media links. 장치(Device) - computer, printer, any other device capable of sending and/or receiving data generated by other nodes on the network. 링크(Link) - communication channel

분산처리(Distributed processing) In which a task is divided among multiple computers. Advantage 1. Security/encapsulation - A system designer can limit the kinds of interactions that a given user can have with the entire system.(ex: ATM(Automated Teller Machine)) 2. Distributed databases - No one system needs to provide storage capacity for the entire database.

분산처리(cont’d) 3. Faster problem solving 4. Security through redundancy - Multiple computers working on parts of a problem concurrently can often solve the problem faster than a single machine working alone. 4. Security through redundancy - Multiple computers running the same program at the same time can provide security through redundancy 5. collaborative processing - Both multiple computers and multiple users may intact on a task(ex: space shuttle)

네트워크 평가기준(Network Criteria) Data communication network criteria Performance Reliability Security

성능(Performance) Depends on a number of factors. number of users type of transmission medium(data rate) hardware software

신뢰성(Reliability) Frequency of failure Recovery time of a network after a failure Catastrophe(큰 재난) Networks must be protected from catastrophic events such as fire, earthquake, or theft.

보안(Security) Unauthorized access Virus

응용(Application) Marketing and sales Financial service Manufacturing Electronic message Directory service Information service Electronic data interchange Teleconferencing Cellular telephone Cable television

1.3 프로토콜과 표준안 (Protocol & Standards) ~ is a set of rules that govern data communication 주요 요소 문법(Syntax) ~ refers to the structure or format of the data, meaning the order in which they are presented. 의미론(Semantics) ~ refers to the meaning of each section of bits. 타이밍(Timing) ~ refers to two characteristics(when data should be sent and how fast it can be sent)

표준안 Standards By fact By law 표준안(Standards) ~ are essential creating and maintaining an open and competitive market for equipment manufactures and in guaranteeing national and international interoperability of data and communications technology and processes. Standards By fact By law

표준안(cont’d) by law standard by fact standard ~ are those that have been legislated by an officially recognized body. by fact standard ~ are often established originally by manufactures seeking to define the functionality of a new product or technology. proprietary(closed) ~ are those originally invented by a commercial organization as a basis for the operation of its products. nonproprietary(open) ~ are those originally developed by group or committees that have passed them into the public domain.

1.4 표준화 기구 Standard Creation Committees ISO(The International Standard Organization) ~ created in 1947 ~ voluntary organization ~ is an organization dedicated to worldwide agreement on international standards in a variety of fields(scientific, technological, economic activity)

표준화 기구(cont’d) ITU-T(International Telecommunication Union - Telecommunication Standards Sector) ~ is an international standards organization related to the United Nations that develops standards for telecommunications. Two popular standards developed by ITU-T are the V series(data transmission over phone lines) and the X series (transmission over public digital networks)

표준화 기구(cont’d) ANSI(American National Standard Institute) ~ is a nonprofit organization and is the U.S. voting representative to be both the ISO and the ITU-T IEEE(Institute of Electrical and Electronic Engineers) ~ is the largest national professional group involved in developing standards for computing, communication, electrical engineering, and electronics) EIA(Electronic Industries Association) ~ is an association of electronics manufactures in the United States. (EIA-232-D, EIA-530 standards)

표준화 기구(cont’d) Bellcore Forums ~ provides research and development resources for the advancement of telecommunications technology. Forums ~ consist of representatives from corporation that test, evaluate and standardize new technologies. Frame Relay Forum ATM Forum and ATM consortium IETF(Internet Society and Internet Engineering Task Force)

1.5 요약