Re: Initial RTT

[Pascal Quantin <pascal.quantin () gmail com>]

2014-07-03 12:45 GMT+02:00 Jasper Bongertz <jasper () packet-foo com>:

> > 2014-07-02 20:59 GMT+02:00 Jasper Bongertz <jasper () packet-foo com>:
>
> > Hello,
> >
> >    as promised during Sharkfest, I checked the latest developer builds
> >    for the accuracy of the calculation of initial RTT for TCP
> >    connections. So far I have only seen correct results, even in cases
> >    with heavy packet loss during the three way handshake. So I think
> >    the code is good.
> >
> >    I also checked traces where the TCP expert was incorrectly assuming
> >    a retransmission when it was in fact an out-of-order packet. Those
> >    are now correctly identified, at least when we have the handshake
> >    and thus initial RTT. Thumbs up for that.
> >
> >    Regarding the way to handle missing handshakes - I would go with the
> >    old 3ms arbitrary value in that case, because most Wireshark
> >    captures are taken in local network environments. Higher values are
> >    problematic because retransmissions are not flagged anymore and
> >    called out-of-order instead, which could lead to a lot of confusion
> >    out there. I prefer false positives for retransmissions over
> >    out-of-orders.
> >
> >    Again, thanks for the effort!
> >
> >  Cheers,
> >  Jasper
>
> > Hi,
>
> > if it is working great (Evan changed the timer back to its old 3ms
> > arbitrary value in case we do not have the handshake) would it make
> > sense to backport this change from the development branch to the
> > 1.12 one (before Wireshark 1.12 gets released)?
>
> > Regards,
> > Pascal.
>
> yes, it would definitely be nice to have it in 1.12 if possible.
>
> Cheers,
> Jasper

Hi Jasper,

it was just merged.

Cheers,
Pascal.

___________________________________________________________________________
Sent via:    Wireshark-dev mailing list <wireshark-dev () wireshark org>
Archives:    http://www.wireshark.org/lists/wireshark-dev
Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev
             mailto:wireshark-dev-request () wireshark org?subject=unsubscribe