From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1567DC48BE5 for ; Wed, 16 Jun 2021 22:34:51 +0000 (UTC) Received: from lists.zx2c4.com (lists.zx2c4.com [165.227.139.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4627F613DB for ; Wed, 16 Jun 2021 22:34:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4627F613DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=wireguard-bounces@lists.zx2c4.com Received: by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 0a2a2344; Wed, 16 Jun 2021 22:34:48 +0000 (UTC) Received: from fudo.makrotopia.org (fudo.makrotopia.org [2a07:2ec0:3002::71]) by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTPS id f7876994 (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO) for ; Wed, 16 Jun 2021 19:26:23 +0000 (UTC) Received: from local by fudo.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.94.2) (envelope-from ) id 1ltbB7-0006vM-Q3; Wed, 16 Jun 2021 21:26:22 +0200 Date: Wed, 16 Jun 2021 21:26:10 +0200 From: Daniel Golle To: "Jason A. Donenfeld" Cc: WireGuard mailing list Subject: Re: passing-through TOS/DSCP marking Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Wed, 16 Jun 2021 22:34:46 +0000 X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" Hi Jason, On Wed, Jun 16, 2021 at 06:28:12PM +0200, Jason A. Donenfeld wrote: > WireGuard does not copy the inner DSCP mark to the outside, aside from > the ECN bits, in order to avoid a data leak. That's a very valid argument. However, from my experience now, Wireguard is not suitable for VoIP/RTP data (minimize-delay) being sent through the same tunnel as TCP bulk (maximize-throughput) traffic in bandwidth constraint and/or high-latency environments, as that ruins the VoIP calls to the degree of not being understandable. ECN helps quite a bit when it comes to avoid packet drops for TCP traffic, but that's not enough to avoid high jitter and drops for RTP/UDP traffic at the same time. I thought about ways to improve that and wonder what you would suggest. My ideas are: * have different tunnels depending on inner DSCP bits and mark them accordingly on the outside. => we already got multiple tunnels and that would double the number. * mark outer packets with DSCP bits based on their size. VoIP RTP/UDP packets are typically "medium sized" while TCP packets typically max out the MTU. => we would not leak information, but that assumption may not always be true * patch wireguard kernel code to allow preserving inner DSCP bits. => even only having 2 differentl classes of traffic (critical vs. bulk) would already help a lot... What do you think? Any other ideas? Cheers Daniel