[e2e] packet loss in the Internet

Stefan Savage savage at cs.ucsd.edu
Thu May 23 20:22:44 PDT 2002


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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