UDP Badness [Was: Re: How to measure network quality&performance for v oip&gameservers (udp packetloss, delay, jitter,...)]

["Fergie" <fergdawg () netzero net>]

The problem with UDP is that there is no explicit feedback-loop
or congestion control frobs -- this is generally kicked up the
protocol stack for the application itself to figure out.

UDP is designed that way: push traffic into the network as fast
as the network can take it, and expect the application to provide
for delay/loss/adaptation of jitter, buffering, etc.

So to answer your question, I think it really depends on how
the application itself handles UDP traffic, adapts to any sort
of RTT measurements, delay/jitter, etc.

- ferg


-- "Gunther Stammwitz" <gstammw () gmx net> wrote:


Hello colleages,

I'm trying to find out how one can measure the performance or quality of a
network for gamers and voip-users.
Both applications are very sensitive to packetloss, delays or jitter since
they're using udp instead of tcp and are very timing critical.

==> Which tools (under linux) are you using in order to measure your own
network ore on of your upstreams in terms of "gameability" or voip-usage?

Ordinary pings won't help since routers are regulary dropping them and even
an end-to-end ping is not perfect since one of the hosts might be busy or
something like that?

Starting your favorite online game and play on a server that is being housed
in your own network isn't the solutions I'm looking for :-(

Your ideas are appreciated :-)



Gunther

--
"Fergie", a.k.a. Paul Ferguson
 Engineering Architecture for the Internet
 fergdawg () netzero net or fergdawg () sbcglobal net
 ferg's tech blog: http://fergdawg.blogspot.com/