From owner-freebsd-net Thu Jul 18 22:21: 4 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1B0B837B400; Thu, 18 Jul 2002 22:20:59 -0700 (PDT) Received: from melete.ch.intel.com (chfdns02.ch.intel.com [143.182.246.25]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8005443E42; Thu, 18 Jul 2002 22:20:58 -0700 (PDT) (envelope-from pavan.balaji@intel.com) Received: from fmsmsxvs042.fm.intel.com (fmsmsxvs042.fm.intel.com [132.233.42.128]) by melete.ch.intel.com (8.11.6/8.11.6/d: solo.mc,v 1.42 2002/05/23 22:21:11 root Exp $) with SMTP id g6J5KwF00491; Fri, 19 Jul 2002 05:20:58 GMT Received: from FMSMSX018.fm.intel.com ([132.233.42.197]) by fmsmsxvs042.fm.intel.com (NAVGW 2.5.2.11) with SMTP id M2002071822214609901 ; Thu, 18 Jul 2002 22:21:46 -0700 Received: by fmsmsx018.fm.intel.com with Internet Mail Service (5.5.2653.19) id <3WZGTSZ4>; Thu, 18 Jul 2002 22:20:57 -0700 Message-ID: <3D386AED1B47D411A94300508B11F18703BC5BD4@fmsmsx116.fm.intel.com> From: "Balaji, Pavan" To: "'Benjamin Franks'" , freebsd-questions@FreeBSD.ORG Cc: freebsd-net@FreeBSD.ORG Subject: RE: giving priority to udp over tcp? Date: Thu, 18 Jul 2002 22:20:55 -0700 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" 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 TCP traffic as such does not get any priority over UDP traffic, but the way in which the TCP messages are sent (Data Streaming) is different from the way UDP messages are sent (Datagram). In essense, UDP messages wait till there's enough space for the entire message before the message is added to the output queue. Whereas, if there isn't enough space for the entire message, a part of the message is sent and the rest buffered. So, it might appear to be getting higher priority for some applications. Pavan Balaji, Intel Corporation "Only the Paranoid Survive" -- Andy Grove > -----Original Message----- > From: Benjamin Franks [mailto:benjamin@dzhan.com] > Sent: Friday, July 19, 2002 12:13 AM > To: freebsd-questions@FreeBSD.ORG > Cc: freebsd-net@FreeBSD.ORG > Subject: giving priority to udp over tcp? > > > > I'm using FreeBSD 4.5 and have custom applications that send receive > network packets over both tcp and udp sockets. For the sake of an > example, assume that the udp traffic is always constant, but the tcp > traffic density changes. During times of heavy tcp traffic > density, will > udp messages which have been sent to the out queue typically > wait in the > queue longer before being sent out? Does tcp traffic get some sort of > priority? If so, is there a way I can de-prioritize tcp > traffic and up > the priority of the udp traffic to make certain all the queued udp > messages get out as soon as possible...? sysctl variables? does it > depend on the network card driver, or perhaps i'm imagining > something that > isn't there and the two traffic types are totally isolated! ;) > > Thanks! > --Ben > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message