[e2e] packet loss in the Internet

Cannara cannara at attglobal.net
Fri May 24 23:31:49 PDT 2002


Stefan, this is a common misconfiguration issue and not an autonegotiation
one, since the difference between FDX & HDX is too great, physically. 
Unfortunately for us all, autonegotiation itself is a typical committeee
product, taking far longer than necessary at startup and having too many
paragraphs in the spec for vendors to choose from.  :]

Alex

Stefan Savage wrote:
> 
> I agree about congestion.  However, I've measured significant loss in
> enterprise networks on several occasions that arose from Ethernet
> full-duplex/half-duplex conflicts (its still not clear to me if the
> Ethernet autonegotiation protocol is fundamentally inadequate or if
> current implementations are simply poor).  Its unclear to me how
> prevalent this problem is, but I've run into it in three separate
> networks.
> 
> - Stefan
> 
> -----Original Message-----
> From: end2end-interest-admin at postel.org
> [mailto:end2end-interest-admin at postel.org] On Behalf Of David P. Reed
> Sent: Thursday, May 23, 2002 3:17 AM
> To: Joe Cao; end2end-interest at postel.org
> Subject: Re: [e2e] packet loss in the Internet
> 
> Typical is the wrong question for enterprise nets.   As Andrew Odlyzko
> has
> noted, enterprise nets are very lightly loaded, and are managed to be
> so,
> except when there are odd constraints or lack of management attention.
> And
> loss rates are *really* low, because congestion is low.   The more
> likely
> congestion problems in enterprise nets is at the endpoints (servers and
> access links).   I observe this in real demos all the time these days,
> where I can demo a particular app that uses uncorrected UDP for voice
> streams (with buffering to eliminate jitter) and can go for hours
> without a
> lost packet.
> 
> Can't speak for ISP
> At 06:14 PM 5/22/2002 -0700, Joe Cao wrote:
> >Hi Folks,
> >
> >Does anyone know in the current real world what a typical packet loss
> >rate is in an enterprise network and on an ISP trunk?  Also if drop
> >occurs, consecutive packets might be discarded.  What is the typical
> >burst
> >size that gets dropped if RED is not enabled?  Are there any such
> >statistics available?  Could anyone get me some pointers that can help
> >me
> >find those information?
> >
> >
> >Thanks!
> >
> >Joe




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