Chrome Timeline指标说明：Blocked、Connect、Send、Waiting、Receiving

Blocked timeincludes any pre-processing time (such as cache lookup) and thetime spent waiting for a network connection to become available.Internet Explorer will only create a maximum of two concurrentnetwork connections per host name (i.e. www.microsoft.com) and willqueue up requests until a network connection is available. Oftenthe Blocked time is the most significant factor in the downloadtime of images embedded in a webpage. 
闭塞时间，包括所有的过程之前的时间（像，cache对比）和等待网络链接的时间，IE在每个主机名（像 http://www.microsoft.com/）下最多只创建两个当前的网络连接，而且要排队等待直到这个网络链接可用，通常，闭塞时间影响网页中图片加载时间的重要因素。
Connect is thetime required to create a TCP connection to the web server (orproxy). If a secure HTTPS connection is being used this timeincludes the SSL handshake process. Keep-Alive connections areoften used to avoid the overhead of repeatedly connecting to theweb server. 
连接时间，是创建TCP连接到服务器或者代理服务器所花费的时间，如果一个包含SSL的安全的HTTPS连接存在，Keep-Alive链接经常被用到，以避免多次重复的连接WEB服务器。
Send is the timerequired to send the HTTP request message to the server and willdepend on the amount of data that is sent to the server. Forexample, long Send times will result from uploading files using anHTTP POST 
发送，是发送HTTP请求到服务器的时间，而且这个时间取决与发送请求的数据量的大小，例如，长的发送时间是由于用PSOT方式上传文件造成的。
Wait is the idletime spent waiting for a response message from the server. Thisvalue includes delays introduced due to network latency and thetime required to process the request on the webserver. 
等待，是花费在等待服务器响应消息的空闲时间，这个值包括网络延迟和服务器处理请求的时间。
Receive is thetime taken to read the response message from the server. This valuewill be depend on the size of the content returned, networkbandwidth and whether HTTP compression wasused. 
接收，是花费在从服务器读取响应消息的时间。这个值可以受到请求消息内容的大小，网络带宽和是否使用了HTTP压缩。
CacheRead is the time taken to read thecontent from the browser cache during (Cache) or 304responses. 
缓存读取，是花费在从浏览器缓存中读取内容或者304响应的时间。
TTFB (or Time ToFirst Byte) is the duration from the initial network request beinginitiated by the browser to the first byte being received from theserver. It includes TCP connection time, the time to send therequest and the time taken to get the first byte of the responsemessage. 
TTFB，是最初的网络请求被发起到从服务器接收到第一个字节这段时间，它包含了TCP连接时间，发送HTTP请求时间和获得响应消息第一个字节的时间。