[188875] in North American Network Operators' Group
Re: Latency, TCP ACKs and upload needs
daemon@ATHENA.MIT.EDU (Mikael Abrahamsson)
Wed Apr 20 11:51:49 2016
X-Original-To: Nanog@nanog.org
Date: Wed, 20 Apr 2016 17:51:44 +0200 (CEST)
From: Mikael Abrahamsson <swmike@swm.pp.se>
To: Jean-Francois Mezei <jfmezei_nanog@vaxination.ca>
In-Reply-To: <5716DB68.1080801@vaxination.ca>
Cc: "Nanog@nanog.org" <Nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On Tue, 19 Apr 2016, Jean-Francois Mezei wrote:
> Considering a single download TCP connection. I am aware that modern TCP
> stacks will rationalize ACKs and send 1 ACK for every x packets
> received, thus reducing upload bandwidth requirements. Is this basically
> widespread and assumed that everyone has that ?
Typically you'll see one ACK per 2 packets, so you need approximately 1:50
bytes up/down ratio for the ACKs.
It's possible to have middle boxes suppress some ACKs, please see thread
here:
https://www.ietf.org/mail-archive/web/aqm/current/msg01482.html
--
Mikael Abrahamsson email: swmike@swm.pp.se
