Timing calculation documentation? SSL Times

Web Performance Discuss Test Results
1

Hello,

I am a frequent user of WPT and absolutey love it. Thanks for all hard work Pat and the community!

Do you have a link to some documentation on how the waterfall size representations are actually calculated from the timers? ( I did take a quick glance at the documentation tab but didnt find it )

I’m trying to do a little troubleshooting on SSL times and I’m having trouble deciphering the timings in the waterfall in comparison to the actual network packets in a capture.

For example what is the start and stop timer of “SSL time” if I wanted to line it up in network packets?

Is the start the TCP connection? The request to the CA? The Changing of Cipher? When is stop calculated? etc…

2

The SSL time reported depends on which browser is being used.

In Firefox and IE it should be based on when the SSL handhake packets start until the HTTP request is sent. I’m not sure if it deals with a pre-connect where the SSL negotiation is done before the connection is actually used.

In Chrome it uses the times reported from dev tools (which can be a bit flaky).