From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailgw1.uni-kl.de (mailgw1.uni-kl.de [IPv6:2001:638:208:120::220]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 438133B29D for ; Sun, 23 May 2021 17:42:33 -0400 (EDT) Received: from [172.20.10.2] (dynamic-046-114-003-126.46.114.pool.telefonica.de [46.114.3.126]) (authenticated bits=0) by mailgw1.uni-kl.de (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id 14NLgMER042172 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Sun, 23 May 2021 23:42:30 +0200 Cc: bloat@lists.bufferbloat.net References: <7FBA3F6F-CBA1-4B19-B48F-10927EDA17A9@gmail.com> From: Erik Auerswald Message-ID: <1a730631-6cc4-8f5d-fa1a-92f9d71ef606@unix-ag.uni-kl.de> Date: Sun, 23 May 2021 23:42:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=1.606, tests=KHOP_HELO_FCRDNS=0.4, MISSING_HEADERS=1.207, NICE_REPLY_A=-0.001 X-Spam-Score: * (1.606) X-Spam-Flag: NO Subject: Re: [Bloat] Educate colleges on tcp vs udp X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 May 2021 21:42:33 -0000 Hi, On 23.05.21 23:02, Jonathan Morton wrote: >> On 23 May, 2021, at 9:47 pm, Erik Auerswald wrote: >> >> As an additional point to consider when pondering whether to >> use TCP or UDP: >> >> To mitigate that simple request-response protocols using UDP >> lend themselves to being abused for reflection and amplification… > > I suspect such considerations are well beyond the level of education requested here. I think what was being asked for was "how do these protocols work, and why do they work that way, in language suitable for people working in a different field", rather than "which one should I use for X application". Yes, I do think so as well. Nevertheless, I want to raise awareness of the risks inherent in building protocols based on UDP. As an optimist, I do believe that it may be possible that in future less new protocols are created that are useful for amplification attacks, by often raising awareness of the risks and how to mitigate them. I would have preferred if the current DDoS attacks using STUN could have been avoided, by allowing standard compliant STUN implementations to have an amplification factor < 1, or at least ≤ 1, and by building response rate limits into the standard. (See, e.g., https://mail.jabber.org/pipermail/operators/2021-April/003130.html) Thanks, Erik