[컴퓨터네트워크] Ch4. Network Layer: Data Plane

4.1 네트워크 계층 개요

1. Forwarding & Routing, Data plane & Control Plane
   1. Two key network layer functions
      • Data plane: Forwarding
      • Control plane: Routing
   2. Two control plane approaches
      • Traditional control plane
      • SDN control plane: remote controller, CA
2. 네트워크 서비스 모델
   • 인터넷: best-effort service

 

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4.2 라우터 내부에는 무엇이 있을까?

1. Input port
   • Forwarding
   • Queueing
2. Switching
   
   • memory
   • bus
   • 3x3 crossbar
     • HOL blocking
   • multistage switch
3. Output port
   • Output port queueing
     1. Drop policy
        • Tail drop
        • Priority
     2. Marking
        • ECN
        • RED
   • Packet scheduling
     1. FIFO
     2. Priority scheduling
     3. Round robin
     4. WFQ
4. Network neurality (망 중립성)

 

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4.3 인터넷 프로토콜(IP): IPv4, IPv4 주소체계, NAT, IPv6

1. IPv4
   • fragmentation/reassembly
2. IPv4 주소체계
   1. Subnet
   2. IPv4 addressing
      • IPv4 careful addressing
      • CIDR
   3. Host는 IP 주소의 host part를 어떻게 얻을까?
      • Hard-coded system
      • DHCP
   4. 기관은 IP 주소의 subnet part를 어떻게 얻을까?
      • Route aggregation - longest prefix matching
   5. ISP는 어떻게 주소 block을 할당받을까?
      • ICANN
3. NAT
   • Nat-enabled router - Nat translation table
4. IPv6
   1. IPv6 datagram format
   2. Translation from IPv4 to IPv6
      • Dual stack router
      • NAT enabled device
      • Tunneling

 

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4.4 Generalized forwarding & SDN

• Forwarding: traditional vs. SDN
• Flow table

 

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4.5 Middlebox