Date: Mon, 30 Aug 1999 17:41:33 -0500 From: Jonathan Lemon <jlemon@americantv.com> To: Mark Murray <mark@grondar.za> Cc: current@FreeBSD.ORG Subject: Re: HEADS UP Message-ID: <19990830174133.34615@right.PCS> In-Reply-To: <199908302140.XAA31558@gratis.grondar.za>; from Mark Murray on Aug 08, 1999 at 11:40:23PM %2B0200 References: <199908302140.XAA31558@gratis.grondar.za>
next in thread | previous in thread | raw e-mail | index | archive | help
On Aug 08, 1999 at 11:40:23PM +0200, Mark Murray wrote: > > I've just committed the revised TCP timer code. There are some > > user visible changes: > : > > Also, some new sysctls have been added: > : > ...&c > > Please let the plebs know, in less kernel-ish terms, what this means? If you don't know that they are, you don't need to worry about them. :-) Seriously, they are allow finer control over some of the TCP behavior. delacktime is related to Nagle's algorithm, and specifies how long a system should delay ACK'ing a packet in hopes that it can collect some data from ther user and piggyback it on top of the ACK packet. flightsize indicates how many packets are allowed to be "in flight", normally, the flightsize is limited to 1 packet at the start of each TCP session, doubles for every ACK received. The intent is that the sender doesn't flood the network (and intervening routers) with a burst of packets, but "slow starts" its transmission. This is normally disabled on "local" networks. Some researchers (Zhang, Floyd) have proposed changing the initial flightsize to 3 to get better performance, recognizing that some of the assumptions about the underlying network are not the same now as they were years ago. msl is the "maximum time" a segment can live in a network, and is the amount of time before a socket can be re-used. Many of these are useful only in specialized applications (or benchamrks!), and it's easier to twiddle a few knobs than to re-compile the kernel each time. -- Jonathan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19990830174133.34615>