tcp下自pudn,
![preview](https://csdnimg.cn/release/downloadcmsfe/public/img/white-bg.ca8570fa.png)
![preview-icon](https://csdnimg.cn/release/downloadcmsfe/public/img/scale.ab9e0183.png)
TCP(Transmission Control Protocol)是一种面向连接的、可靠的、基于字节流的传输层通信协议,是互联网协议族中最核心的部分之一。它确保了数据在互联网中的准确无损传输,为应用层提供了全双工的数据通信服务。TCP通过三次握手建立连接,四次挥手释放连接,确保了数据传输前的准备和传输后的清理工作。 在TCP中,每个数据段都有序号和确认应答号,用于跟踪数据包的顺序和确认接收。如果发送方没有收到确认,会进行重传,这就是TCP的可靠性保障。同时,TCP还具备流量控制和拥塞控制机制,避免网络拥塞并确保数据传输的平滑进行。 流量控制是通过滑动窗口机制实现的,允许发送方根据接收方的反馈调整发送速率,防止接收方来不及处理过多的数据。拥塞控制则是在网络状况变差时,减缓数据的发送速率,通常采用慢启动、拥塞避免、快速重传和快速恢复等策略。 TCP头部包含了源端口号、目的端口号、序列号、确认应答号、数据偏移、保留、标志位(如SYN、ACK、FIN等)、窗口大小、校验和以及紧急指针等字段,这些字段共同协作完成TCP的各种功能。 在TCP连接管理中,"三次握手"是建立连接的过程:第一次握手,客户端发送带有SYN标志的数据段请求连接;第二次握手,服务器响应一个SYN+ACK的数据段,确认并请求连接;第三次握手,客户端再发送一个ACK数据段,确认连接建立。而"四次挥手"则是断开连接:第一次挥手,主动关闭方发送FIN标志的数据段;第二次挥手,被动关闭方发送ACK确认;第三次挥手,被动关闭方发送FIN标志的数据段;第四次挥手,主动关闭方发送ACK确认,连接正式关闭。 在"tcp下自pudn"可能是指在TCP协议下,用户从pudn(可能是某个资源分享网站或论坛)下载文件的情景。在下载过程中,TCP负责将大文件分割成多个数据段进行传输,并确保每个数据段都能正确到达,即使在网络不稳定的情况下也能通过重传机制保证数据的完整性。 总结来说,TCP是一种保证可靠性的网络传输协议,通过连接管理、序列号、确认应答、流量控制和拥塞控制等机制,确保了数据在网络中的安全、高效传输。在实际应用中,如从pudn下载文件,TCP协议扮演着至关重要的角色,保证了文件传输的完整性和一致性。
![application/x-rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![gz](https://img-home.csdnimg.cn/images/20210720083447.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![package](https://csdnimg.cn/release/downloadcmsfe/public/img/package.f3fc750b.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/RAR.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/RAR.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/RAR.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/JPG.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![folder](https://csdnimg.cn/release/downloadcmsfe/public/img/folder.005fa2e5.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/GIF.png)
![file-type](https://csdnimg.cn/release/download/static_files/pc/images/minetype/UNKNOWN.png)
- 1
![avatar-default](https://csdnimg.cn/release/downloadcmsfe/public/img/lazyLogo2.1882d7f4.png)
![avatar](https://profile-avatar.csdnimg.cn/bcf05fc98b2e43879bd9585f40f8035f_wswh2o.jpg!1)
- 粉丝: 3
- 资源: 29
我的内容管理 展开
我的资源 快来上传第一个资源
我的收益
登录查看自己的收益我的积分 登录查看自己的积分
我的C币 登录后查看C币余额
我的收藏
我的下载
下载帮助
![voice](https://csdnimg.cn/release/downloadcmsfe/public/img/voice.245cc511.png)
![center-task](https://csdnimg.cn/release/downloadcmsfe/public/img/center-task.c2eda91a.png)
最新资源
![feedback](https://img-home.csdnimg.cn/images/20220527035711.png)
![feedback-tip](https://img-home.csdnimg.cn/images/20220527035111.png)
![dialog-icon](https://csdnimg.cn/release/downloadcmsfe/public/img/green-success.6a4acb44.png)