UDP Badness [Was: Re: How to measure network quality&performance for v oip&gameservers (udp packetloss, delay, jitter,...)]
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/
-----Ursprüngliche Nachricht----- Von: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] Im Auftrag von Fergie Gesendet: Dienstag, 7. März 2006 18:16 An: gstammw@gmx.net Cc: nanog@nanog.org Betreff: UDP Badness [Was: Re: How to measure network quality&performance for voip&gameservers (udp packetloss, delay, jitter,...)]
[...]
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
Hello Fergie, You are right - but there must be some sort of tool that can generate udp packets at a specified rate (or bandwidth) and measure if they are arriving in order, if there is loss and what the jitter is or something like that. Does anyone know some kind of tool? Gunther
On 07/03/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
-----Ursprüngliche Nachricht----- Von: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] Im Auftrag von Fergie Gesendet: Dienstag, 7. März 2006 18:16 An: gstammw@gmx.net Cc: nanog@nanog.org Betreff: UDP Badness [Was: Re: How to measure network quality&performance for voip&gameservers (udp packetloss, delay, jitter,...)]
[...]
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
Hello Fergie,
You are right - but there must be some sort of tool that can generate udp packets at a specified rate (or bandwidth) and measure if they are arriving in order, if there is loss and what the jitter is or something like that. Does anyone know some kind of tool?
Gunther
Iperf comes to mind. /Tony
________________________________ Von: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] Im Auftrag von tony sarendal Gesendet: Dienstag, 7. März 2006 19:05 An: nanog@nanog.org Betreff: Re: UDP Badness [Was: Re: How to measure network quality&performance for voip&gameservers (udp packetloss, delay, jitter,...)] Iperf comes to mind. /Tony Hello Tony, Thanks for the tip. I've already been using iperf but wasn't that perfectly satisfied. I'm looking for something else - maybe even something with a graphical output. Any other ideas? Gunther
On 07/03/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
________________________________
Von: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] Im Auftrag von tony sarendal Gesendet: Dienstag, 7. März 2006 19:05 An: nanog@nanog.org Betreff: Re: UDP Badness [Was: Re: How to measure network quality&performance for voip&gameservers (udp packetloss, delay, jitter,...)]
Iperf comes to mind.
/Tony
Hello Tony,
Thanks for the tip. I've already been using iperf but wasn't that perfectly satisfied. I'm looking for something else - maybe even something with a graphical output. Any other ideas?
Gunther
Unfortunately not. Iperf has suited me fine where I don't require professional (pricey) testers. The fact that it is console based I usually see as a plus. -- Tony Sarendal - dualcyclone@gmail.com IP/Unix -= The scorpion replied, "I couldn't help it, it's my nature" =-
Unfortunately not. Iperf has suited me fine where I don't require professional (pricey) testers. The fact that it is console based I usually see as a plus. -- Tony Sarendal - dualcyclone@gmail.com IP/Unix -= The scorpion replied, "I couldn't help it, it's my nature" =- -- Well that's true but Iperf won't show you at which time a loss occured. It will simply print out the results when the test has been finished. I need something well more accurate that can also tell me which hop is causing the problems.
On 07/03/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
Well that's true but Iperf won't show you at which time a loss occured. It will simply print out the results when the test has been finished. I need something well more accurate that can also tell me which hop is causing the problems.
Last I checked I got the time from Iperf, even if it was indirectly.
A tool that shows which hop in the network that has problems forwarding certain traffic ? Awesome, I want one of those. -- Tony Sarendal - tony@polarcap.org IP/Unix -= The scorpion replied, "I couldn't help it, it's my nature" =-
On Tue, 7 Mar 2006 23:33:44 +0000 "tony sarendal" <dualcyclone@gmail.com> wrote:
On 07/03/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
Well that's true but Iperf won't show you at which time a loss occured. It will simply print out the results when the test has been finished. I need something well more accurate that can also tell me which hop is causing the problems.
Last I checked I got the time from Iperf, even if it was indirectly.
A tool that shows which hop in the network that has problems forwarding certain traffic ? Awesome, I want one of those.
traceroute ? :-) (sorry, couldn't resist) -- "Sheep are slow and tasty, and therefore must remain constantly alert." - Bruce Schneier, "Beyond Fear"
On 10/03/06, Mark Smith < random@72616e646f6d20323030342d30342d31360a.nosense.org> wrote:
On Tue, 7 Mar 2006 23:33:44 +0000 "tony sarendal" <dualcyclone@gmail.com> wrote:
On 07/03/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
Well that's true but Iperf won't show you at which time a loss
occured. It
will simply print out the results when the test has been finished. I need something well more accurate that can also tell me which hop is causing the problems.
Last I checked I got the time from Iperf, even if it was indirectly. A tool that shows which hop in the network that has problems forwarding certain traffic ? Awesome, I want one of those.
traceroute ? :-) (sorry, couldn't resist)
Does traceroute really do that ? Even for ICMP. Think about it. Hint: the return packets your traceroute produces, do they have the same return path for every hop ? Think Internet, think large providers with many peerings. /Tony -- Tony Sarendal - tony@polarcap.org IP/Unix -= The scorpion replied, "I couldn't help it, it's my nature" =-
On Fri, Mar 10, 2006 at 11:52:40AM +0000, tony sarendal wrote:
Does traceroute really do that ? Even for ICMP. Think about it.
Hint: the return packets your traceroute produces, do they have the same return path for every hop ?
Think Internet, think large providers with many peerings.
On behalf of every network operator on the planet, I would like to take this opportunity to encourage every person who implements a traceroute or traceroute like program to ALWAYS DISPLAY THE SOURCE ADDRESS IN THE OUTPUT OF THE PROGRAM!@#$%^& Very few things in life suck more than asymmetric paths + wannabe network engineers armed with a noc phone number list and traceroute, mtr, or those wonderful visual traceroute programs that they insist on taking 6MB bmp screenshots of and sticking into word documents so they can email that as an attachment. -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
On Fri, 10 Mar 2006, Richard A Steenbergen wrote:
On Fri, Mar 10, 2006 at 11:52:40AM +0000, tony sarendal wrote:
Does traceroute really do that ? Even for ICMP. Think about it.
Hint: the return packets your traceroute produces, do they have the same return path for every hop ?
Think Internet, think large providers with many peerings.
On behalf of every network operator on the planet, I would like to take this opportunity to encourage every person who implements a traceroute or traceroute like program to ALWAYS DISPLAY THE SOURCE ADDRESS IN THE OUTPUT OF THE PROGRAM!@#$%^&
Very few things in life suck more than asymmetric paths + wannabe network engineers armed with a noc phone number list and traceroute, mtr, or those wonderful visual traceroute programs that they insist on taking 6MB bmp screenshots of and sticking into word documents so they can email that as an attachment.
You will not learn hatred until that MMO you host implements a 'Report network problem' button that does a traceroute, and automatically emails it and a canned message to your NOC mailbox. Ultima Online did this, back in my nocling days. Like monkeys expecting a reward, those little bastards pounded on that button until the lag stopped. It gave the west coast sucking sound that was Mae-West an entirely different flavor. We could monitoring peering conditions based solely on mailbox volume. - billn
On Fri, 10 Mar 2006, Bill Nash wrote:
You will not learn hatred until that MMO you host implements a 'Report network problem' button that does a traceroute, and automatically emails it and a canned message to your NOC mailbox. Ultima Online did this, back in my nocling days. Like monkeys expecting a reward, those little bastards pounded on that button until the lag stopped.
That's hilarious- I just finished emailing ras offlist about the same tool. It also (somehow) allowed them to send their blather to hostmaster@ea.com. http://matt.snark.net/crap/idiot/idiot5.txt matto --matt@snark.net------------------------------------------<darwin>< The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke
On Fri, Mar 10, 2006 at 11:43:59AM -0800, Matt Ghali wrote:
On Fri, 10 Mar 2006, Bill Nash wrote:
You will not learn hatred until that MMO you host implements a 'Report network problem' button that does a traceroute, and automatically emails it and a canned message to your NOC mailbox. Ultima Online did this, back in my nocling days. Like monkeys expecting a reward, those little bastards pounded on that button until the lag stopped.
That's hilarious- I just finished emailing ras offlist about the same tool. It also (somehow) allowed them to send their blather to hostmaster@ea.com.
Not to try and troubleshoot your 5 year old ticket or anything, but their ingress traceroute shows what looks like Baltimore to San Francisco to mae-west to a sjc based server (probably someone honoring meds :P), and the outbound traceroute used to troubleshoot it coming out of VA and going over mae-east. Nothing in that traceroute proves that AboveNet was or was not having issues at mae west. While the output from traceroute is simple, obtaining meaningful data from it about what is actually wrong requires an operator with expertise and years of experience. Jumping to conclusions about what is or isn't wrong based on traceroute is probably one of the largest failings of noc people in general. But thanks for reminding us of the crappy crappy networking that went on 5 years ago. :) -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
--On Tuesday, March 07, 2006 18:59:27 +0100 Gunther Stammwitz <gstammw@gmx.net> wrote:
You are right - but there must be some sort of tool that can generate udp packets at a specified rate (or bandwidth) and measure if they are arriving in order, if there is loss and what the jitter is or something like that. Does anyone know some kind of tool?
iperf. http://dast.nlanr.net/Projects/Iperf/ I regularly use iperf to stress test various network components. In TCP mode it will show you how fast a tcp stack can negotiate to, in UDP mode it can throw packets at a fixed rate and the server can tell you how many it got. There is also NDT, http://e2epi.internet2.edu/ndt/, but that requires a kernel with the web100 patches to instrument the kernel network stack. -David Nolan Network Software Designer Computing Services Carnegie Mellon University
Does anyone know some kind of tool?
The CAIDA tools taxonomy is a good place to start shopping for a tool like this: http://www.caida.org/tools/taxonomy/performance.xml Then do some googling on the names which interest you to see what people are saying about them. Packetloss, delay and jitter are IP characteristics, not UDP. In any network that allows IP packets to be lost or to be buffered, there will be delay and jitter. --Michael Dillon
on Vendor C, SAA probes can get you this info.. you then monitor with SNMP... On 3/8/06, Michael.Dillon@btradianz.com <Michael.Dillon@btradianz.com> wrote:
Does anyone know some kind of tool?
The CAIDA tools taxonomy is a good place to start shopping for a tool like this: http://www.caida.org/tools/taxonomy/performance.xml Then do some googling on the names which interest you to see what people are saying about them.
Packetloss, delay and jitter are IP characteristics, not UDP. In any network that allows IP packets to be lost or to be buffered, there will be delay and jitter.
--Michael Dillon
On 3/7/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
Does anyone know some kind of tool?
Just as I suspected: no one outside of the lab uses tools like owamp for real-world monitoring. aaron.glenn
-----Ursprüngliche Nachricht----- Von: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] Im Auftrag von Aaron Glenn Gesendet: Freitag, 10. März 2006 19:45 An: Gunther Stammwitz Cc: nanog@nanog.org Betreff: Re: UDP Badness [Was: Re: How to measure network quality&performance for voip&gameservers (udp packetloss, delay, jitter,...)]
On 3/7/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
Does anyone know some kind of tool?
Just as I suspected: no one outside of the lab uses tools like owamp for real-world monitoring.
OWAMP = http://e2epi.internet2.edu/owamp/ ?
On 3/11/06, Gunther Stammwitz <gstammw@gmx.net> wrote:
OWAMP = http://e2epi.internet2.edu/owamp/ ?
Correct. aaron.glenn
participants (11)
-
A Satisfied Mind -
Aaron Glenn -
Bill Nash -
David Nolan -
Fergie -
Gunther Stammwitz -
Mark Smith -
Matt Ghali -
Michael.Dillon＠btradianz.com -
Richard A Steenbergen -
tony sarendal