Date: Tue, 01 May 2001 23:04:32 -0700 From: Julian Elischer <julian@elischer.org> To: =?iso-8859-1?Q?R=E9mi?= Guyomarch <rguyom@pobox.com> Cc: Gunther Schadow <gunther@aurora.regenstrief.org>, snap-users@kame.net, freebsd-net@freebsd.org, ipfilter@coombs.anu.edu.au, altq@csl.sony.co.jp Subject: Re: The future of ALTQ, IPsec & IPFILTER playing together ... Message-ID: <3AEFA370.28562F63@elischer.org> References: <3AEEEE79.8F7CC7B0@aurora.regenstrief.org> <3AEEF26B.C6850070@isi.edu> <3AEEF59D.3D5622DE@aurora.regenstrief.org> <20010501205741.A30269@diabolic-cow.chatgris.net> <3AEF0E6A.2E9B34A0@aurora.regenstrief.org> <20010501235602.B30269@diabolic-cow.chatgris.net>
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Rémi Guyomarch wrote: > > On Tue, May 01, 2001 at 07:28:42PM +0000, Gunther Schadow wrote: > > Rémi Guyomarch wrote: > > > > > IIRC you can put a bandwidth limiter on a virtual interface (this is > > > even the only solution to use ALTQ on tun or ppp devices) and thus > > > provide a queue which can be managed by ALTQ. > > > > Aha! A Light! How is that done? Can you give more specifics? > > Look at docs/TIPS.txt in the altq-3.0 release, point 1.9 : > > ... > 1.9 Tun Driver > Although altq-3.0 supports the tun driver, it is a bit tricky to > control the tun device. > > When ppp transmits packets the tun interface is not a bottleneck > but the serial port is the bottleneck. As a result, packets are > queued in the output queue of ppp and the buffer in the kernel > as shown in the following figure. (a queued packet is shown as X.) > > ppp > app ---+ +-->[ XXX]--+ > | | | > user | | | > ==========|==============|===========|===== > kernel | | | > | +------+ | | > +-->| |---+ +->[ XX]--> sio > +------+ line > tun0 discipline > > To control traffic at the tun interface, rate-limit the tun > interface by a token-bucket regulator to shift the queueing point > to the tun device as shown in the following figure. > > ppp > app ---+ +-->[ ]--+ > | | | > user | | | > ==========|==============|===========|===== > kernel | | | > | +------+ | | > +-->| XXXXX|---+ +->[ ]--> sio > +------+^tbr line > tun0 discipline > > Note that ppp usually compress packets so that the throughput at > the tun interface will be much higher than the line rate. the above picture is only true for ppp if you use mpd it is as follows: > > app ---+ > | > user | > ==========|================================ > kernel | > | +------+ ppp > +-->| |---+-->[ ]--+->[ ]--> sio > +------+^tbr line > ng0 discipline > > ... > -- __--_|\ Julian Elischer / \ julian@elischer.org ( OZ ) World tour 2000-2001 ---> X_.---._/ v To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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