Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 09 Sep 2004 08:31:31 +0900
From:      "George V. Neville-Neil" <gnn@neville-neil.com>
To:        Julian Elischer <julian@elischer.org>
Cc:        net@freebsd.org
Subject:   Re: [Fwd: TCP RTO]
Message-ID:  <m2k6v4nxrg.wl@minion.local.neville-neil.com>
In-Reply-To: <413F54EE.1020700@elischer.org>
References:  <413F54EE.1020700@elischer.org>

next in thread | previous in thread | raw e-mail | index | archive | help
At Wed, 08 Sep 2004 11:52:30 -0700,
julian wrote:
> My curiosity is if we see the tcp.cc code inside, 

tcp.cc ?  That's not a kernel file.

> there are two different version of srtt (smoothed rtt) and rttvar
> (smoothed mean deviation estimator). The one is simply 'srtt' and
> 'rttvar' and the other is 't_srtt' and 't_rttvar'. The unit of
> t_srtt is 'ticks * 8' and the unit of t_rttvar is 'ticks * 4'.

In -CURRENT, and I would suspect most recent versions of FreeBSD, the
only variables I find are t_srtt and t_rttvar which are used as fixed
point values.  srtt and rttvar were variables used in the older (BSD
4.4?) code.  I believe they were documented in Steven's TCP/IP
Illustrated Volume 2 but I don't have my copy here so I can't check.

Later,
George



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?m2k6v4nxrg.wl>