From 5ee8448ad7c306f05a9f56769f95336a8269f379 Mon Sep 17 00:00:00 2001 From: "job@openbsd.org" Date: Wed, 4 Apr 2018 15:12:17 +0000 Subject: upstream: Update default IPQoS in ssh(1), sshd(8) to DSCP AF21 for interactive and CS1 for bulk AF21 was selected as this is the highest priority within the low-latency service class (and it is higher than what we have today). SSH is elastic and time-sensitive data, where a user is waiting for a response via the network in order to continue with a task at hand. As such, these flows should be considered foreground traffic, with delays or drops to such traffic directly impacting user-productivity. For bulk SSH traffic, the CS1 "Lower Effort" marker was chosen to enable networks implementing a scavanger/lower-than-best effort class to discriminate scp(1) below normal activities, such as web surfing. In general this type of bulk SSH traffic is a background activity. An advantage of using "AF21" for interactive SSH and "CS1" for bulk SSH is that they are recognisable values on all common platforms (IANA https://www.iana.org/assignments/dscp-registry/dscp-registry.xml), and for AF21 specifically a definition of the intended behavior exists https://tools.ietf.org/html/rfc4594#section-4.7 in addition to the definition of the Assured Forwarding PHB group https://tools.ietf.org/html/rfc2597, and for CS1 (Lower Effort) there is https://tools.ietf.org/html/rfc3662 The first three bits of "AF21" map to the equivalent IEEEE 802.1D PCP, IEEE 802.11e, MPLS EXP/CoS and IP Precedence value of 2 (also known as "Immediate", or "AC_BE"), and CS1's first 3 bits map to IEEEE 802.1D PCP, IEEE 802.11e, MPLS/CoS and IP Precedence value 1 ("Background" or "AC_BK"). OK deraadt@, "no objection" djm@ OpenBSD-Commit-ID: d11d2a4484f461524ef0c20870523dfcdeb52181 --- readconf.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'readconf.c') diff --git a/readconf.c b/readconf.c index 88051db57..f69b46547 100644 --- a/readconf.c +++ b/readconf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.c,v 1.283 2018/02/23 15:58:37 markus Exp $ */ +/* $OpenBSD: readconf.c,v 1.284 2018/04/04 15:12:17 job Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1998,9 +1998,9 @@ fill_default_options(Options * options) if (options->visual_host_key == -1) options->visual_host_key = 0; if (options->ip_qos_interactive == -1) - options->ip_qos_interactive = IPTOS_LOWDELAY; + options->ip_qos_interactive = IPTOS_DSCP_AF21; if (options->ip_qos_bulk == -1) - options->ip_qos_bulk = IPTOS_THROUGHPUT; + options->ip_qos_bulk = IPTOS_DSCP_CS1; if (options->request_tty == -1) options->request_tty = REQUEST_TTY_AUTO; if (options->proxy_use_fdpass == -1) -- cgit v1.2.3