컴퓨터네트워크(CSE3212-002) 전범위 강의 필기노트

2024 인하대학교 컴퓨터공학과 전공수업

목차

[컴퓨터네트워크] 01. What is the network?

• 💖 What is a Network?
  • 네트워크란?
  • Node란?
  • Link란?

[컴퓨터네트워크] 02. Protocol과 Standard

• 💖 What is a Protocol?
  • Protocol이란 무엇인가요?
  • Protocol의 3요소
    • 1. Syntax
    • 1. Semantics
    • 1. Timing
• 💖 What is a Standard?
  • Standard란 무엇인가요?
  • Standard Development Organization(SDO)
    • IETF
    • De facto standards
• 💖 Protocol Layering Basics
  • Protocol Layering이 탄생한 배경
  • Protocol Set이란 무엇인가요?
  • Basic Terms in Protocol Layering
    • Service
    • Protocol
    • Interface
    • Definitions of Protocols
  • Protocol Graph
    • Protocol Graph란 무엇인가요?
  • Protocol Encapsulation
    • Protocol Encapsulation이란?
    • Protocol Encapsulation과 Decapsulation

[컴퓨터네트워크] 03. OSI Reference Model

• Reference Model이란 무엇인가요?
• OSI Reference Model이란 무엇인가요?
• ⚡ Layer 1: Physical Layer
• ⚡ Layer2: Data link layer
  • Service
  • MAC이란?
• ⚡ Layer3: Network layer
  • Fragmentation
  • Packet scheduling
• ⚡ Layer4: Transport Layer
• ⚡ Layer5: Session Layer
• ⚡ Layer6: Presentation Layer
• ⚡ Layer7: Application Layer
• 💖 OSI Refernece Model
  • Intermediate Node

[컴퓨터네트워크] 04. Protocol Data Units(PDU)

• Protocol Data Units(PDU))
  • PDU의 탄생 배경

[컴퓨터네트워크] 05. TCP/IP Protocol Suite

• Protocol layering 복습
  • Protocol layering은 왜 필요한가요?
• TCP/IP Protocol Suite

[컴퓨터네트워크] 06. Multiplexing

• Multiplexing이란 무엇인가요?
  • Multiplexing and Demultiplexing
• Multiplex를 구현하는 방법 2가지

[컴퓨터네트워크] 07. Circuit Switching과 Packet Switching

• 💖 Curcuit Switching
  • Circuit Switching이란?
  • Curcuit Switching을 구현하는 방법 2가지
    • ⚡️ TDM(Time Division Multiplexing)
    • ⚡️ FDM(Frequency Division Multiplexing)
• 💖 Packet Switching
  • Packet Switching이란?
  • Circuit Switching VS Packet Switching
  • Internet에서 Packet Switching의 과정

[컴퓨터네트워크] 08. Packet Scheduling

• 💖 Packet Scheduling
  • Packet Scheduling in Gateway
  • Queueing and Packet Loss
  • Queuing in Internet
• 💖 Packet delay
  • Nodal Delay란?
  • Nodal Delay를 구하는 공식
  • ⚡ Transmission delay
    • bps란 무엇인가요?
  • ⚡️ propagation delay
  • ⚡️ Nodal processing delay
  • ⚡️ Queueing delay
  • Throughput이란 무엇인가요?
  • Throughput 구하는 공식
  • Bottleneck link
  • Round Trip Time(RTT)
• BDP

[컴퓨터네트워크] 09. Ethernet

• 💖 Ethernet
  • Ethernet의 방식 2가지
  • ⚡ Bus 방식이란?
  • ⚡ Switched 방식이란?
• 💖 Wireless LANs
  • Rate Adaptation
• 💖 References

[컴퓨터네트워크] 10. CSMA/CD

• 💖 CSMA/CD
  • CSMA/CD의 탄생 배경
  • CSMA/CD란?

[컴퓨터네트워크] 11. Wide Area Networks (WANs)

• 💖 Wide Area Networks (WANs)
  • WAN 기술들
  • ⚡ Cable-based access
    • frequency division multiplexing (FDM)
    • Hybrid Fiber Coax
  • ⚡ Digital subscriber line (DSL)
  • ⚡ Cellular networks

[컴퓨터네트워크] 12. Network Connecting Devices

• 💖 Connecting Devices
  • 우리가 배울 Connecting Devices들

[컴퓨터네트워크] 13. Repeater (Hub)

• ⚡ Repeater(Hub)란?
  • Repeater의 문제점

[컴퓨터네트워크] 14. Bridge (2 layer switch)

• ⚡ Bridge(2 layer switch)란?
• Destination Address Learning
  • Destinattion Address Learning 과정
  • Transparent한 Switch란?

[컴퓨터네트워크] 15. Router

• ⚡ Router

[컴퓨터네트워크] 16. TCP와 UDP

• 💖 TCP와 UDP
  • TCP VS UDP
  • ⚡ TCP Protocol
    • TCP Protocol의 특징
    • TCP Protocol에서 제공하는 기능 3가지
  • Connection-oriented Multiplexing
    • Multiplexing
    • Demultiplexing
  • UDP Protocol이란?
    • UDP Protocol의 특징
    • UDP Protocl의 장점
    • TCP/UDP segment format
  • Connectionless demultiplexing
    • Multiplexing
    • Demultiplexing
• 💖 References

[컴퓨터네트워크] 17. Connection-oriented

• 💖 Connection
• Transport Layer Basics
  • Connection-oriented demultiplexing
  • 네트워크에서의 Connection
    • Connectionless
    • Connection-Oriented

[컴퓨터네트워크] 18. TCP Header

• 💖 TCP Header and Encapsulation
  • TCP Header의 구성
    • ⚡ ACK
    • ⚡ application data(acknowledgement number)
    • ⚡ checksum
    • ⚡ options
    • ⚡ headlen
    • ⚡ sequence number
    • ⚡ RST, SYN, FIN
    • ⚡ receive window
    • ⚡ C, E
    • ⚡Urg data pointer
  • Pseudoheader
• 💖 References

[컴퓨터네트워크] 20. Three-Way Handshake

• 💖 Connection Establishment
• 💖 Three-Way Handshake
  • TCP Packets
    • ⚡ SYN
    • ⚡ ACK
    • ⚡ seq
    • ⚡ ack
    • ⚡ rwnd
  • Three-Way Handshake의 연결 수립
  • 일반적인 상황에서 TCP의 데이터 Communication
  • Connection Termination
• 💖 References

[컴퓨터네트워크] 21. Special Cases in TCP Connection Management

• TCP Connection에서의 예외 케이스
• ⚡ Simultaneous Open
  • TCP Hole Punching
• ⚡ TCP Half-Close
• ⚡ Simultaneous Close

[컴퓨터네트워크] 22. ISN

• 💖 ISN(Initial Sequence Number)
  • ISN

[컴퓨터네트워크] 23. TCP Options

• 💖 Timeout of Connection Establishment
  • Timeout의 도입 배경
• 💖 TCP Options
  • Options
  • 중요한 Options
    • ⚡ MSS
    • ⚡ WSOPT
    • ⚡ SACK
    • ⚡ TSOPT
  • Path MTU Discovery with TCP (Optional)

[컴퓨터네트워크] 24. TCP State Diagram

• 💖 TCP State Diagram
  • State Transition Diagram
    • 3-way handshake 과정
    • 둘 중 하나가 Close를 호출했을 때
    • 2MSL
• 💖 Reset Segment
  • Reset segment가 사용되는 경우

[컴퓨터네트워크] 25. ARQ

• 💖 ARQ
  • ARQ란 무엇인가요?
  • ARQ가 필요한 시나리오
  • ARQ는 어떻게 구현할 수 있나요?
    • ⚡ Stop-and-wait
    • ⚡ Go-back-N(GBN)
    • ⚡ Selective-Repeat

[컴퓨터네트워크] 26. TCP Sliding Window

• 💖 TCP Sliding Window
  • Sliding Window의 도입 배경
  • Byte-oriented, Sender-side Sliding Window Protocol
    • 그림을 이해해보자…
    • 시나리오 1: Time out
  • Sliding Window Size의 결정

[컴퓨터네트워크] 27. TCP Flow Control

• 💖 TCP Flow Control
  • 도입 배경
  • Flow Control이란?
  • TCP의 Flow Control
    • Producer-Consumer 관점에서의 TCP Flow Control 예시
    • Packet 관점에서의 TCP Flow Control 예시

[컴퓨터네트워크] 28. Nagles’s Algorithm

• 💖 Issues regarding Variable Window Size
  • Silly Window Syndrome란?
  • 어떤 상황에 발생하나요?
  • Nagle’s algorithm
    • 구현 방법
  • Clark’s solution

[컴퓨터네트워크] 29. TCP Error Control

• 💖 TCP Error Control
  • TCP의 Error Control 기법
  • Sender의 error control
    • 언제 발생하나요?
  • ACK Generation 규칙들
  • Error Control Scenario
    • Normal Operation
    • Lost Segment
    • Lost ACK corrected by resending a segment
    • Fast Retransmission
    • Lost ACK
  • Retransmission Timeout 설정
    • Naïve Round-Trip Time (RTT) Estimation
    • SmoothedRTT Estimation
    • RTT Variation Estimation
  • TCP’s RTO Computation Algorithm
• 💖 Referneces

[컴퓨터네트워크] 30. TCP Congestion Control

• 💖 TCP Congestion Control
  • Congestion이란?
  • Congestion control
    • Congestion을 예측하는 방법
  • Congestion 발생 시나리오
    • case 1. output link buffer가 infinite할 때
    • case 2. finite buffer
    • Case 3. duplication까지 발생했을 때
• 💖 Congestion Control 방법
  • End-end congestion control
  • Network-assisted congestion control

[컴퓨터네트워크] 31. AIMD algorithm

• AIMD algorithm
  • AIMD에서 sending rate를 조절하는 방법
  • ⚡ Additive Increase
  • ⚡ Multiplicative Decrease

[컴퓨터네트워크] 32. TCP Slow Start

• TCP slow start
  • 등장한 배경
  • 구현 방법
• AIMD와 slow start의 결합
  • 각각의 사용 목적

[컴퓨터네트워크] 33. TCP Fairness

• TCP Fairness
  • Fairness란?
  • TCP에서의 faireness
  • Q. TCP는 fair한가요?
• 💖 다양한 network에서의 Fairness
  • UDP에서의 Fairness
  • Parallel TCP Connection에서의 Fairness
    • 예시
• 💖 References

[컴퓨터네트워크] 34. TCP Timers

• 💖 TCP Timers
  • TCP Timers
  • TCP Timer의 종류
  • ⚡ Keepalive Timer
  • ⚡ Persistance Timer
    • Persistance Timer의 등장 배경
    • 발생 시나리오

[컴퓨터네트워크] 35. Name and Address in BSD Socket

• 💖 Address and Name in BSD Sockets API
  • Internet에서 Address와 Name
    • Name
    • Address
  • IPv4 Address
    • network byte order vs host byte order
  • Resolution
• 💖 References

36. Network layer

• 💖 Netwrok layer란?
  • Network layer는 어떤 역할을 하나요?
  • Router의 역할
• 💖 Netwrok layer의 기능
  • Network layer의 2가지 기능
  • ⚡ forwarding
  • ⚡ routing
• 💖 Network layer 내부의 두 plane
  • Plane
    • ⚡ Data Plane
    • ⚡ Control Plane
    • Software-Defined Networking (SDN) control plane

37. Internet Service Model

• 💖 Network service model
  • Internet service model
    • best effort service

38. IPv4

• 💖 Internet Protocol (IP) Version 4
  • Internet Protocol의 service
    • ⚡ Unreliable
    • ⚡ Connectionless

39. IP header

• 💖 IP Header
  • IPv4의 Datagram
    • ⚡ version
    • ⚡ IHL
    • ⚡ Total Length
    • ⚡ Identification
    • ⚡ TTL(Time-to-live)
    • ⚡ Protocol
    • ⚡ Header Checksum
  • IPv6의 Datagram
    • ⚡ Next Header

40. IPv4 Options

• 💖 IPv4 Options
  • ⚡ No operation
  • ⚡ Record route
  • ⚡ Pointer
  • ⚡ Source Route Options
    • Strict Source Route Options
    • Loose Source Route Options
  • ⚡ Timestamp Option

41. IP Addressing

• 💖 IP Addressing
  • IPv4의 주소 notation
  • IPv6의 주소 notation
    • IPv6의 Simplification
• 💖 Classful Addressing
  • Class 별 Network ID
    • Class D: Multicase address
    • class E
  • class 별 Default Mask
• 💖 IP Header
  • IPv4의 Datagram
    • ⚡ version
    • ⚡ IHL
    • ⚡ Total Length
    • ⚡ Identification
    • ⚡ TTL(Time-to-live)
    • ⚡ Protocol
    • ⚡ Header Checksum
  • IPv6의 Datagram
    • ⚡ Next Header

[42. Netword Address Translation (NAT)]

• 💖 Network Address Translation
  • 필요한 배경
  • 변환 방식
  • NAT 방식의 장단점
    • 장점
    • 단점

[43. Adress Resolution Protocol (ARP)]

• 💖 MAC Address
  • MAC 주소란?
    • MAC 주소의 예시
  • Layer 관점에서의 MAC 주소
• 💖 ARP
  • ARP란?
  • ARP의 동작 방식
  • ARP cache
    • 예시
  • Gratuitous ARP
    • 예시
    • 왜 필요한가요?
  • Routing to Another Subnet

44. DHCP

• 💖 DHCP
  • Dynamic Host Configuration Protocol
  • DHCP의 과정

45. Internet Control Message Protocol (ICMP)

• 💖 Internet Control Message Protocol (ICMP)
  • ICMP
  • ICMP의 format
    • 기본 메시지 포맷
    • ICMP의 datafield
  • ICMP message types
    • ⚡ Time Exceeded
    • ⚡ ICMP redirect message
    • ⚡ Traceroute
    • Stopping criteria

46. Multiprotocol Label Switching (MPLS)

• 💖 Multiprotocol label switching (MPLS)
  • MPLS
    • circuit switching과 packet switching
    • Virtual Circuit
  • MPLS가 사용되는 시나리오
  • MPLS signaling

47. HTTP

• 💖 HTTP와 Web
  • HTTP 개요
    • server와 client
    • HTTP의 layer
    • stateless
• 💖 Persistent HTTP
  • HTTP의 두가지 종류
  • ⚡ Non-persistent HTTP
    • Non-persistent HTTP 동작
  • ⚡ Persistent HTTP(HTTP/1.1)
    • Persistent HTTP의 등장 배경
    • Persistent HTTP
    • Persistent HTTP with pipelining
• 💖 HTTP request message
  • Reuest message header
    • ⚡ Host
    • ⚡ User-Agent
    • ⚡ Accept-Encoding
    • ⚡ Connection
  • Request message format
• 💖 HTTP response message
  • response message 예시
  • response status codes
• 💖 Cookies
  • 예시
    • tracking a user’s browsing behavior

48. Domain Name Service (DNS)

• 💖 Domain Name Service
  • Top-Level Domain
  • Internet Assigned Numbers Authority
    • Delegation record
  • DNS Zone
  • DNS Records
    • 기본 포맷
    • Type=A
    • Type=NS
    • Type=CNAME
    • Type=MX
  • DNS Protocol
• 💖 References

49. Internet Routing Protocols

• 💖 IP Routing Protocols
  • IP Routing Protocol
  • Graph abstraction
  • Routing algorithms의 분류
    • ⚡ Global VS Decentralized
    • ⚡ Static VS Dynamic
  • Autonomous Symstems(AS)
• 💖 Intra-AS routing과 Inter-AS routing
  • ⚡ Intra-AS Routing Protocols
    • 💛 Routing Information Protocol(RIP)
    • 💛 Enhanced Interior Gateway Routing Protocol(EIGRP)
    • 💛 Open Shortest Path First(OSPF)
  • ⚡ Inter-AS routing
    • 💛 BGP
• 💖 Routing Algorithms
  • ⚡ link state algorithm
    • 예시
    • Discussion
    • Dijkstra’s algorithm: oscillations possible
  • ⚡ Distance vector
    • Bellman-Ford Equation
    • Good news travels fast
• 💖 References