Three-Way Handshake The following scenario occurs when a TCP connection is established: The server must be prepared to accept an incoming connection. This is normally done by calling socket, bind, and listen and is called a passive open. The client i…

不多说了,先上个图: 从上面的图中可以看出来,基于TCP协议进行通讯可以大致分成以下几个阶段: 1. 首先是在服务器端, TCP Sever调用socket(), bind(), listen()完成初始化.然后调用accept()阻塞等待,处于监听端口的状态. 2. 客户端调用socket()初始化后,调用connect()发出SYN段并阻塞等待服务器应答,服务器应答一个SYN-ACK段,客户端收到后从connect()返回, 同时应答一个ACK段,服务器收到后从accept()返回.这也就是…

常见的性能测试工具有: loadRunner/netperf/httperf/apache_ab/Apache JMeter , 其中loadRunner属于付费软件,所以在这里不做介绍 netperf(HP公司维护的开源项目) 主要用来测量大数据量传输的时性能, 这也称作流或者单向流性能. 主要用来度量一个系统接收或者发送的数据有多快, 最简单的命令如下: /opt/netperf/netperf -H remotehost 此外, tcp_stream_script和tcp_range_sc…

文字版 使用https httpstat https://10.24.101.14/cwbase/web/Login.aspx --insecure Connected to HTTP/ OK Server: nginx/ Date: Mon, Sep :: GMT Content-Type: text/html; charset=utf- Content-Length: Connection: keep-alive Cache-Control: private X-AspNet-Version…

httpstat 应该是一个 python 封装后的 curl 工具能够展现 一些客户端连接网站的时间消耗,最近在看tls 感觉挺有用处的 简单学习一下 1. centos7 安装python 和 pip yum intall python -y #安装python curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py #下载pip安装文件 python get-pip.py #安装pip 2. 安装httpstat模块 pip inst…

https://code.google.com/p/nsscache/wiki/BackgroundOnNameServiceSwitch The POSIX API POSIX is a standard that defines an operating system interface and its environment; describing available library calls, utilities, environment vars, escape sequences,…

TCP, relative to the SOCKET developers create process and link remove process consists of the TCP/IP protocol stack is automatically created. So the developer doesn't need to control this process. But to understand TCP the underlying mechanism is qui…

TCP Connection Management Out-of-Order and Duplication(复制) Problem Old segment from previous connections to come Use long sequence number (32-bits) Establish randomly selected initial sequence number (ISN) Accept sequence numbers from a small window(…

http://www.inetdaemon.com/tutorials/internet/tcp/3-way_handshake.shtml…

TCP是面向连接的协议,其数据传输过程分为建立连接.数据传送.释放连接三个阶段. 0 建立连接 建立连接的过程也就是常说的"三次握手": 客户端向服务器端发送一个SYN报文(SYN=1表示这是一个连接请求或连接接收报文),并随机选取一个起始序号x: 服务器端应答一个SYN报文,同时ACK(确认位)置1[ACK=1时TCP报文段首部中的ack(确认号字段)才有效],随机选取一个服务器端的起始序号y,并将ack字段设为x+1,表示已经收到客户端发来的SYN报文,期待收到序号为x+1的下一个…