1.INTRODUCTION
The Transmission Control Protocol （TCP） is intended for use as a highly reliable host-to-host protocol between hosts in packet-switched computer communication networks, and in interconnected systems of such networks.This document describes the functions to be performed by the Transmission Control Protocol, the program that implements it, and it interface to programs or users that require its services.

Motivation:
Computer communication systems are playing an increasingly important role in minitary, government, and civilian environments.This document focuses its attention primarily on military computer communication requirements, especially robustness in the presence of communication unreliability and availability in the presence of congestion, but many of these problems are found in the civilian and government sector as well.

1、is intended for……： 用于，目的是，为……准备的
2、packet-switched：包交换，分组交换
3、interconnected: 连通的，有联系的
4、Motivation： 动机
5、robustness 稳健性，健壮性
6、congestion： 拥挤，拥塞