Re: [Bloat] [tsvwg] [aqm] how much of a problem is buffer bloat today?

["Scheffenegger, Richard" <rs@netapp.com>]

Hmm...


TCP measures RTT; 

one could create a global histogram of all measured RTTs by TCP (whenever a valid measurement is taken), and export that with "netstat -sp tcp"... Of course, vastly different paths would be gobbled up together, but when investigating specific paths, that should be good enough as a high level starting point.




Richard Scheffenegger


> -----Original Message-----
> From: tsvwg-bounces@ietf.org [mailto:tsvwg-bounces@ietf.org] On Behalf Of
> Mirja Kuehlewind
> Sent: Dienstag, 26. März 2013 18:26
> To: aqm@ietf.org
> Cc: bloat; tsvwg@ietf.org
> Subject: Re: [tsvwg] [aqm] [Bloat] how much of a problem is buffer bloat
> today?
> 
> Hi,
> 
> +1. Would be nice to have such statictics available for the user in every
> OS!
> 
> Mirja
> 
> 
> On Friday 22 March 2013 05:27:31 Mikael Abrahamsson wrote:
> > On Thu, 21 Mar 2013, Jim Gettys wrote:
> > > Every more modern TCP can easily fill any sized buffer given time
> > > with a single TCP connection.
> >
> > I agree with this, I made this discovery myself back in 2004 or so,
> > and had to implement Fairqueue and WRED on my home connection to make
> > it bearable to use any interactive application while transferring files.
> >
> > In IETF75 in Stockholm in 2009, I made proposals in both TCP and at
> > open mic in one of the sessions, that I would like to see statistics
> > and performance numbers on packet loss, delay variation etc from
> > actual traffic. The IP stack has great insight in what the network
> > conditions are (especially with TCP Timestamping), but as far as I
> > know it's not really exported in any usable format to the user. My
> > idea was to have some kind of dashboard for the user to show if
> > currently the network was the limiting factor, if the tcp window was
> > maxed out etc. Would also be nice if there was output that could be
> > cut/pasted and attached to a fault report in case the customer talks
> > to customer support. It would be good if this was actually a standard so
> all OSes did the same.
> >
> > I am not aware of any such work going on, so I'd like to know if
> > anyone else is aware of work in this area?
> 
> 
> 
> --
> -------------------------------------------------------------------
> Dipl.-Ing. Mirja Kühlewind
> Institute of Communication Networks and Computer Engineering (IKR)
> University of Stuttgart, Germany Pfaffenwaldring 47, D-70569 Stuttgart
> 
> tel: +49(0)711/685-67973
> email: mirja.kuehlewind@ikr.uni-stuttgart.de
> web: www.ikr.uni-stuttgart.de
> -------------------------------------------------------------------