Network Programming: Syllabus
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Transcript of Network Programming: Syllabus
Network Computing Lab. (http://nclab.chonbuk.ac.kr)1
Network Programming:Syllabus
Spring 2009,
Prof. Kihyun Pyun
Evolution of Data Communication Networks (1) A key motivation
A typical key cost : communication media installation cost
Equipments are relatively cheap!
Evolution of Data Communication Networks (2) If a new technology requires a new
network infrastructure, reconsider it! Is it worth for investing a BIG money? As an example, think about the video
conferencing technologies in 1970s xDSL technologies are good examples for
success
Evolution of Data Communication Networks (3) Due to a tremendous initial investment
for a network backbone infrastructure traditionally telecommunication companies
leads the trend• E.g., FrameRelay, ATM (Asynchronous Transfer
Mode), … existing infrastructures are reused as much
as possible• However, equipments can be replaced more
easily than transmission media
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Evolution of Data Communication Networks (4)
인터넷 서비스 제공자(ISP)
ISP
라우터 PC
서버노트북
가정망
회사망
LAN
WAN
저비용 , 이더넷
고비용 , 기존망 활용
( 케이블 모뎀 ,xDSL, etc)
인터넷 망 전체 구조
무선 AP
Evolution of Data Communication Networks (5) An example
컴퓨터 전화 모뎀 전화모뎀
( )컴퓨터 고성능 컴퓨터
컴퓨터 전화 모뎀 전화모뎀
컴퓨터 전화 모뎀 전화모뎀
인터넷
인터넷 검색 인터넷 연결을 위한 중간 다리 역할
가정
가정
가정
전화망
~ Km ,수십 수백 거리56 Kbps 이하
Evolution of Data Communication Networks (6)
컴퓨터 ADSL 모뎀분리기
(splitter)
중계기(MSLAM)분리기
(splitter)
인터넷
전화망
전화선로
300 m ,이하 거리10 Mbps 이상
가정
컴퓨터 ADSL 모뎀분리기
(splitter)
분리기(splitter)
전화선로가정
300 m ,이하 거리10 Mbps 이상
Another example
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Figure 16.1 Connecting devices
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Figure 16.2 Repeater
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Figure 16.3 Function of a repeater
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Figure 16.4 Hubs
Dummy hub : multi-port repeater
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Figure 16.12 Star backbone
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004 Introduction 1-13
Residential access: cable modems
Diagram: http://www.cabledatacomnews.com/cmic/diagram.html
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004 Introduction 1-14
Cable Network Architecture: Overview
home
cable headend
cable distributionnetwork (simplified)
Typically 500 to 5,000 homes
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004 Introduction 1-15
Cable Network Architecture: Overview
home
cable headend
cable distributionnetwork (simplified)
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004 Introduction 1-16
Cable Network Architecture: Overview
home
cable headend
cable distributionnetwork
server(s)
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004 Introduction 1-17
Cable Network Architecture: Overview
home
cable headend
cable distributionnetwork
Channels
VIDEO
VIDEO
VIDEO
VIDEO
VIDEO
VIDEO
DATA
DATA
CONTROL
1 2 3 4 5 6 7 8 9
FDM:
McGraw-Hill ©The McGraw-Hill Companies, Inc., 2004
Evolution of Data Communication Networks (6) A short history
Telegraphiccommunication
Telephonenetworks
Telephone andData networks
Message Voice Voice, data
ISDN(Integrated
ServicesDigital Network)
Voice, video, data
B-ISDN(Broadband
ISDN)
Internet
Voice, video, data
Data, voice by VoIP, video
Analog wirelesscommunications
Digital wirelesscommunications
GSM CDMACDMA2000,
HSDPA, …
Voice Voice Voice Voice, data Voice, video, data
ALL IP ?!Winner?
Network Computing Lab. (http://nclab.chonbuk.ac.kr)
프로토콜 스택 (Protocol Stack)
다양한 통신선과 장비가 서로 통신할 수 있도록 정한 규약들 전화선 , 동선 , 광케이블 등 국제 표준화가 필요
Layering 을 통해 복잡성을 줄임 하위 계층의 기능을 상위 계층에서 활용
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Network Computing Lab. (http://nclab.chonbuk.ac.kr)
ISO 의 OSI reference model
OSI (Open Systems Interconnection) reference model ISO 에서 만듦 7 계층 참고 모델일 뿐 !
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Application
Presentation
Session
Transport
Network
Data Link
Physical
Introduction 1-21
Internet protocol stack application: supporting network
applications FTP, SMTP, STTP
transport: host-host data transfer TCP, UDP
network: routing of datagrams from source to destination IP, routing protocols
link: data transfer between neighboring network elements PPP, Ethernet
physical: bits “on the wire”
application
transport
network
link
physical
Introduction 1-22
Protocol layering and data
Each layer takes data from above adds header information to create new data unit passes new data unit to layer below
applicationtransportnetwork
linkphysical
applicationtransportnetwork
linkphysical
source destination
M
M
M
M
Ht
HtHn
HtHnHl
M
M
M
M
Ht
HtHn
HtHnHl
message
segment
datagram
frame
스택구조로 사용먼저 넣은 것이 가장 늦게 나옴
Network Computing Lab. (http://nclab.chonbuk.ac.kr)
토론 마당
새로운 선 , 예들 들면 USB 선에 연결된 마우스를 인터넷에서 접속하는 것이 가능할까 ? 어떻게 ?
혹은 CDMA 망에 인터넷은 어떻게 ?
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CDMA
Physical
IP
TCP
CDMA
Physical
Network Computing Lab. (http://nclab.chonbuk.ac.kr)
프로토콜 예제
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Ethernet
UTP
TCP/IP
X.25/…
Coaxial
TCP/IP
WCDMA/Wibro
Wireless channel
TCP/IP
Ethernet
UTP
TCP/IP
X.25/…
Coaxial
TCP/IP
WCDMA/Wibro
Wireless channel
TCP/IP
하부망 특정 프로토콜( 예 : ARP, RARP)
하부망 특정 프로토콜( 예 : 기지국 찾기 , …)
네트워크 프로그래밍은 넓은 관점에서는 위의 모든 프로토콜 영역에 적용할 수 있어야 함 .그러나 하부망 특정 프로토콜 영역은 ( 소켓프로그래밍에서 Raw 패킷 ) 이 과목에서 주로 다루지 않음
Network Computing Lab. (http://nclab.chonbuk.ac.kr)
고려해야 할 프로토콜들
TCP 오류없는 데이터 전송 보장
UDP 효율적인 데이터 전송 ( 패킷 소실 가능 )
응용 프로토콜 FTP, Telnet, …
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TCP UDP
IP
FTP HTTP RIPOSPF