From owner-freebsd-net Wed May 22 16:59:12 2002 Delivered-To: freebsd-net@freebsd.org Received: from iguana.icir.org (iguana.icir.org [192.150.187.36]) by hub.freebsd.org (Postfix) with ESMTP id 8854937B404; Wed, 22 May 2002 16:59:07 -0700 (PDT) Received: (from rizzo@localhost) by iguana.icir.org (8.11.6/8.11.3) id g4MNx0543380; Wed, 22 May 2002 16:59:00 -0700 (PDT) (envelope-from rizzo) Date: Wed, 22 May 2002 16:59:00 -0700 From: Luigi Rizzo To: John Baldwin Cc: net@FreeBSD.ORG Subject: Re: Lossless bandwidth limiter on an interface Message-ID: <20020522165900.B43026@iguana.icir.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from jhb@FreeBSD.ORG on Wed, May 22, 2002 at 05:42:56PM -0400 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org when a dummynet queue drops UDP packets, it returns an ENOBUF error on the write(), so you can at least retry the transmission yourself after some time. Unfortunately there is not any mechanism in place to make an UDP write() blocking. cheers luigi On Wed, May 22, 2002 at 05:42:56PM -0400, John Baldwin wrote: > I'm curious: what would be the best method of implementing a bandwith limiter > on an interface that is lossless? I'm having to limit UDP with no back channel, > so I can't reply on TCP retransmits to make up for packets being dropped. > DUMMYNET drops packets that overflow it's queue size so it doesn't seem to work > out of the box. Ideally, I would like applications sending packets to the > interface to block when the outgoing queue is full. One idea I thought > about is trying to use netgraph to implement a network interface that does > this limiting and then hands the data off to a real network interface that > it is attached to, but I also don't want to have to add netgraph support to > a bunch of network drivers to get this to work either. > > Suggestions? > > -- > > John Baldwin <>< http://www.FreeBSD.org/~jhb/ > "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message