Re: Iperf: UDP question
Hello
I also got similar results when I run Iperf version
1.7.0 in 2 PC´s with 100 Mbps cards, connected through a switch. Initially
both nodes got Windows XP, then I tested in one node with Windows Server 2003
and the second node with Windows XP, to see if I got any difference, but results
were the same.
For TCP, I got nearly 94 Mbps but for UDP I got
approximately
60 Mbps. I agree that UDP should be faster but I haven´t figured out yet why
this is happening.
The command I used to get that UDP throughput
was:
iperf -c serveraddress -u -b
100G <---
Observe that I used a bit rate higher than system
bandwidth
iperf -s -u
The only way I got a better UDP throughput
(around 91 Mbps) was changing the socket buffer size (-w) and the datagram
length (-l). I used the following commands to do so:
iperf -c serveraddress -u -b
100G -w 128k -l 32k
iperf -s -u -w 128k -l 32k
I will also appreciate if someone knows what is
happening.
Thanks, Rosanna
----- Original Message -----
Sent: Monday, September 12, 2005 9:16
PM
Subject: Iperf: UDP question
> Hi,
> I've been using IPerf for doing some tests
on our
> network. For TCP tests, I'm able to get around 94
>
mbps between two systems. However, the speed drops to
> around 30
mpbs over UDP. Shouldn't UDP be faster?
>
> I've googled this
but haven't come up with a good
> answer. Is it IPerf not doing the
measurements
> correctly or is it something with Windows XP?
>
> The commands I'm using are:
>
> iperf -c -u myserversIP -b
100M -p 5002
>
> iperf -s -u
>
> If someone can give
me some clues on this I'd really
> appreciate it.
>
> Also,
is there a webpage that lists the max, min, and
> default parameter values
for things such as packet
> size, etc for Windows and Linux?
>
> Thanks
>
> Najaf
>
>