Sorry for the late reply. Note that people actively work on fixing bug 
862856 <https://bugzilla.mozilla.org/show_bug.cgi?id=862856>. Let's see if 
the problem goes away once that issue is closed.

Sebastian

On Wednesday, November 12, 2014 at 1:24:34 PM UTC+1, 
[email protected] wrote:
>
> Thanks Sebastian.
>
> Just a minor clarification - the issue is with both Connect time and DNS.
>
> It sounds like I might have to go back to a Firefox release that is about 
> 2 years old in order to get a working version.   That worries me!   Is 
> there another group I should post a message on to see if there is any hope 
> of getting this fixed?  I wonder if the W3C Navigation Timings are bogus 
> too.
>
> I realize that tracking performance when the platform includes things such 
> as DNS prefetch and anticipatory connections can become very complex.  I am 
> hoping that the Firefox team considers providing accurate performance 
> information as a priority.
>
> - Les
>
> On Monday, November 10, 2014 8:30:47 PM UTC-7, 
> [email protected] wrote:
>>
>> I am trying to verify that the timings in the Network panel are accurate. 
>>  This is for an application performance analysis utility I am developing 
>> for a client.
>>
>> I am using a network emulator to force additional artificial latency into 
>> the network.
>>
>> My test preconditions are to clear the windows DNS (ifconfig /flushdns), 
>> and set Firefox not to cache any DNS entries (network.dnsCacheExpiration 
>> and network.dnsCacheEntries both set to 0).
>>
>> I am trying to validate what I see in the net panel is correct by using 
>> Wireshark to see the actual network traffic.  The results prove that the 
>> DNS lookup and connect are being lumped into blocking time.
>>
>> I am using a static image from my own website to test.  I am adding about 
>> 225ms of RTT latency.
>>
>>
>> http://www.eperformancegroup.com/blog/wp-content/plugins/slideshow-gallery/views/default/images/left.gif?test=xxx
>>
>> The FB network panel shows blocking of 843ms, waiting of 283ms
>>
>> Wireshark shows DNS lookup time of 567ms
>> Wireshark shows TCP connect of 275ms.  Add in DNS time and the total is 
>> 842ms.
>> Wireshark shows response time of 284ms
>>
>> So - the total times match up - but the network panel lumped both the DNS 
>> time and the TCP connect time into blocking.
>>
>> Can this be easily fixed / is there a workaround I might use?    HAR file 
>> is attached.
>>
>> FF 33.1,  Firebug 2.0.6
>>
>> In a repeat test, I can confirm that this is repeatable.
>>
>> FB net panel shows blocking of 620ms, wait of 284ms
>>
>> "timings": {
>>           "blocked": 620,
>>           "dns": 0,
>>           "connect": 0,
>>           "send": 0,
>>           "wait": 284,
>>           "receive": 0
>>         },
>>
>> For the repeat test:
>>
>> Wireshark shows DNS of 341 ms
>> Wireshark TCP connect time of 274 ms - a total of 615ms
>> wireshark shows response time of 283 ms
>>
>>
>> <https://lh5.googleusercontent.com/-d9v5R_kJSK4/VGGA2Xhq64I/AAAAAAAAAAM/ROyp-c_ZgGM/s1600/FB%2Bnetwork%2Bpanel.png>
>>
>>
>>
>>
>>
>>
>>
>>
>> <https://lh5.googleusercontent.com/-1_ADrfv5OKQ/VGGA5xNczhI/AAAAAAAAAAU/Hj1V73S8Ubc/s1600/DNS%2Blookup%2B576ms.png>
>>
>>
>>
>> <https://lh6.googleusercontent.com/-WK_RIPk6KhI/VGGA_-O9z-I/AAAAAAAAAAc/CXMTVp26GHk/s1600/TCP%2Bconnect%2B275ms.png>
>>
>>
>>
>> <https://lh6.googleusercontent.com/-yJE4gR-dDAs/VGGBC2a5T1I/AAAAAAAAAAk/m3k_bcboS7E/s1600/response%2B284ms.png>
>>
>>
>>
>>
>>

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