소프트웨어융합개론
의개념 컴퓨터, 즉컴퓨팅기능을가진시스템들이물리적인매체로서로연결되어데이터를교환하는시스템들의모임 단말시스템 (end system), 중개시스템 (intermediate system) ISP (Internet Service Provider) 개인이나기업체에게인터넷접속서비스를제공하는회사 Internet: a network of networks
단말네트워크와코아네트워크 단말네트워크 홈액세스네트워크 (Home Access Network) 기업액세스네트워크 무선액세스네트워크 코아네트워크 Circuit Switching Packet Switching 네트워크의네트워크 ISP IXP
네트워크프로토콜 데이터교환이어떤절차를거쳐어떤형식으로이루어지는가를규정해놓은약속 메시지의형식 메시지의각요소의의미 각메시지를송신하기전후의조치 각메시지를수신한후의조치 계층적구조
네트워크프로토콜 계층적구조
네트워크프로토콜 OSI(Open System Interconnection) Model ISO 에서제안된일곱계층의네트워크프로토콜모델 물리계층 (physical layer) : ( 예, 인터페이스의물리적규격 ). 링크계층 (link layer): ( 예, 오류복구, 링크접근제어 ). 네트워크계층 (network layer): ( 예, 송신단말과수신단말간의경로설정 ). 전송계층 (transport layer): ( 예, 오류복구, 혼잡제어, 흐름제어 ). 세션계층 (session layer): ( 예, 단말간연결설정 ). 표현계층 (presentation layer): ( 예, 압축, 암호화 ). 응용계층 (application layer): 응용서비스를구현한프로세스들간의요청메시지와응답메시지를교환하는과정을정의한다.
TCP/IP 프로토콜 Suite OSI 모델과같이계층적구조를갖고있으나 5 개의계층으로구성 물리계층, 링크계층 ( 혹은네트워크접속계층 ), 네트워크계층 ( 혹은인터넷계층 ), 전송계층, 응용계층으로구성 물리계층은 OSI 모델과거의동일 링크계층은 OSI 의링크계층과네트워크계층의일부에걸쳐대응 전송계층은 OSI 의전송계층과세션계층의일부에걸쳐대응 응용계층은 OSI 의세션계층일부, 표현계층, 응용계층에걸쳐대응된다.
인터넷의역사 인터넷이라는용어가사용된것은 1990 년대초부터이고, 이인터넷의기원이되는는 1969 년미국에서 ARPAnet 이라는이름으로시작 1961 년에패킷스위칭에관련된이론이제시 1962 년에 "Galactic ( 은하계 ) network" 이라는개념이소개 Advanced Research Projects Agency Network (ARPANET) Promoted to the head of the information processing office at DARPA, The first ARPANET link was established between the University of California, Los Angeles (UCLA) and the Stanford Research Institute at 22:30 hours on October 29, 1969. 우리나라에서는 1982 년에서울대와대구의전자기술연구소의컴퓨터가네트워크를구성한것이국내인터넷의기원 IETF (Internet Engineering Task Force), ICANN (Internet Corporation for Assigned Names and Numbers) [
World Wide Web (WWW or W3,Web) a system of interlinked hypertext documents accessed via the Internet hypertext : containing units of text, images, sound, and video that may be linked to other documents hypermedia : same another term expanded to formats other than text 전세계를 ( 거미줄처럼 ) 연결하는 hypertext / hypermedia 망 Computer scientist and at that time employee of CERN, Sir Tim Berners-Lee, now Director of the World Wide Web Consortium (W3C), wrote a proposal in March 1989 for what would eventually become the World Wide Web By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web:[9] the first web browser (which was a web editor as well); the first web server; and the first web pages,[
World Wide Web Browser: allows user to access web pages web client (= web browser) user interface to browse within the web Netscape, Internet Explorer Web server: provides access to documents on its machine as requested containing documents to be accessed Hypertext Transfer Protocol (HTTP): communication protocol used by browsers and web servers Uniform Resource Locator (URL): unique address of a document on the we
Internet 구성요소 도메인네임시스템 1983 년에 Paul Mockapetris 에의해서제안 세가지구성요소 : 도메인이름공간 (domain name space) 리소스레코드 (resource record) 네임서버 (name server) 네임리졸버 (name resolver) IP (Internet Protocol) IP 는초기에 TCP 의기능의일부였으나, 그기능의중요도가높아지면서 1981 년에 IP version 4 로분리 인터넷에연결된네트워크와네트워크내에속한단말시스템을구분하기위한주소체계를제공 IP 의주소체계는계층구조 IPv4 의경우, 32 bit 를사용하여주소를표시