ChromeDriver - Network Performance Logging: Understanding timing section of Network.responseReceived

Question

I am trying to understand the relationship between the attributes in the timing section of network performance log message.

Setup: I am running ChromeDriver with Network Performance Logging. I am pulling out the log messages (Selenium - Java). Below is sample log message and my understanding so far.

message => params => response => timing
{
    "requestTime": 126550.470936,          : Time in sec when the browser knows the call has to be issued?
    "proxyStart": 1.77299999631941,        : Is this a relative time in ms from requestTime? What this latency accounts for?
    "proxyEnd": 3.25700000394136,          : Time taken to resolve the proxy in ms?
    "dnsStart": -1,                        :  
    "dnsEnd": -1,                          : Time taken to resolve the dns?
    "connectStart": -1,                    :
    "connectEnd": -1,                      : Time taken to establish the connection with remote server? 
    "sslStart": -1,                        :
    "sslEnd": -1,                            : Is this part of "connect" section? (time taken to negotiate SSL handshake?)
    "workerStart": -1                      :
    "workerReady": -1,                     : 
    "sendStart": 582.229000006919,         : 
    "sendEnd": 582.65900000697,            : Time taken to send the request to server?
  "pushEnd": 0,                          :
    "pushStart": 0,                        : Unclear as what this accounts for.
    "receiveHeadersEnd": 1218.61900000658  : Time taken to completely receive the header?
}

I am trying to understand the following parts from the above timing split.

• Time taken by browser to issue the request (typical Queuing delay visible in network tab).
• Time taken by the browser to establish the connection and send the request
• Time taken by the server to process the request
• Time taken to receive the response.

Any pointers on this will be great.

Answer 1

I got the answers from another group https://groups.google.com/forum/#!topic/google-chrome-developer-tools/FCCV2J7BaIY