Network metering - transport layer

This article mainly introduces the following aspects of knowledge ：

1. Transport layer Overview
2. UDP agreement
3. TCP agreement

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1. Transport layer Overview

(1) Transport layer functions

(2) Two protocols in the transport layer

(3) Addressing and port of transport layer

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2.UDP agreement

(1)UDP Overview of the agreement

(2)UDP Format of the first part

(3)UDP check

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3.TCP agreement

(1)TCP Agreement features and TCP Message segment

• TCP Characteristics of the agreement
  
• TCP Message segment
  
  
  

(2)TCP Connection management

• TCP Connection is established
  
  
• TCP Connection release
  
  
• SYNS Flooding attack
  

(3)TCP Reliable transmission

• check
  Same as UDP Same verification , Use pseudo header for verification
• Serial number
  
• confirm
  
• Retransmission
  
• The fast retransmission
  

(4)TCP flow control

• Example ：
  

(5)TCP Congestion control

• Slow start & Congestion avoidance
  
• Fast retransmission & Fast recovery