From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: dynamic TCP algorithms switching Date: Fri, 22 Nov 2013 14:56:21 -0800 Message-ID: <20131122145621.344fa999@nehalam.linuxnetplumber.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-net@vger.kernel.org To: yan cui Return-path: Received: from mail-pb0-f53.google.com ([209.85.160.53]:49269 "EHLO mail-pb0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756256Ab3KVW4Z (ORCPT ); Fri, 22 Nov 2013 17:56:25 -0500 Received: by mail-pb0-f53.google.com with SMTP id ma3so1915698pbc.26 for ; Fri, 22 Nov 2013 14:56:25 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 22 Nov 2013 17:49:58 -0500 yan cui wrote: > Hi all: > > Currently, Linux has kinds of TCP congestion algorithms, such as > reno, cubic, bic, hybla, ...., and each TCP congestion algorithm has > its target networking environment. I just wonder to know is it > possible to do dynamic TCP algorithm switching? In other words, the > system has a combined TCP congestion algorithm (say, TCP-auto), and it > behaves like one of the integrated TCP congestion algorithms according > to different detected networking environment, but can switch to a > different one. For example, TCP-auto totally uses the set of > congestion control operations in TCP-cubic by default, but when it > detects that the current OS uses wireless networking, it switches to > some wireless friendly TCP congestion algorithm. Does Linux have some > features like that, or do you (networking developers and users) care > about it? > > Best Wishes! > You overestimate the advantage of one verus the other. It is possible to control algorithm on per-socket, and per-route but other than benchmarking there or bulk transfer for normal net traffic Cubic works fine for all environments.