[netperf-talk] Questions on UDP_STREAM test

[Jay Kim]

Thank you, Rick.
Now I figured out how I can use the options. (I was reading the old manual page. Sorry.)

Please see the following output (for other people).

$ netperf -H demeter -t UDP_STREAM -w 100 -b 100 -- -m 100
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to demeter (10.89.1.122) port 0 AF_INET : interval
Socket  Message  Elapsed      Messages                
Size    Size     Time         Okay Errors   Throughput
bytes   bytes    secs            #      #   10^6bits/sec

  8192     100   9.99        10000      0       0.80
  8192           9.99        10000              0.80


$ netperf -H demeter -t UDP_STREAM -w 100 -b 200 -- -m 100
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to demeter (10.89.1.122) port 0 AF_INET : interval
Socket  Message  Elapsed      Messages                
Size    Size     Time         Okay Errors   Throughput
bytes   bytes    secs            #      #   10^6bits/sec

  8192     100   10.00       20000      0       1.60
  8192           10.00       20000              1.60


$ netperf -H demeter -t UDP_STREAM -w 200 -b 200 -- -m 100
UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to demeter (10.89.1.122) port 0 AF_INET : interval
Socket  Message  Elapsed      Messages                
Size    Size     Time         Okay Errors   Throughput
bytes   bytes    secs            #      #   10^6bits/sec

  8192     100   10.00       10000      0       0.80
  8192           10.00        9922              0.79

- jay


----- Original Message ----- 
From: "Rick Jones" <rick.jones2 at hp.com>
To: "Jay Kim" <jay.m.kim at samsung.com>
Cc: <netperf-talk at netperf.org>
Sent: Tuesday, January 08, 2008 10:28 AM
Subject: Re: [netperf-talk] Questions on UDP_STREAM test


> Jay Kim wrote:
>> Hi, I'm learning netperf now.
>> 
>> When using UDP_STREAM tests, I have the following questions. Would you please answer these?
>> 
>> 1) Doesn't netperf provide parameters to control packet interval? For
>> UDP test, I'm thinking to set a fixed data rate with a packet size and a
>> packet interval parameters as iperf does. The packet size seems to be
>> set by using '-m' option, but, I couldn't find how to control packet
>> intervals. Am I missing something?
> 
> Sadly, that part isn't terribly well documented in:
> 
> http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html
> 
> ./configure --enable-intervals ...
> 
> or
> 
> ./configure --enable-spin ...
> 
> and recompile netperf in its entirety.
> 
>> 2) I thought that -w option (when compiling with --enabale-intervals)
>> would be for controlling the interval, but it didn't work. What does
>> this 'interval' mean?
> 
> Please be explicit in what you mean by didn't work.  When netperf is 
> configured with --enable-intervals or --enable-spin - and recompiled - 
> then the global -w option will set how often burst of up to -b sends 
> will be send.  However, if it takes longer than the interval specified 
> by -w to send that burst, behaviour is undefined - on many platforms the 
> test may end prematurely.
> 
>> 3) What can I do if I want to run a UDP overload test, that is,
>> sending UDP packet stream of rate more than actual network link
>> capacity? Is it not possible with netperf?
> 
> Depends on the stack.  Some stacks have intra-stack flow control which 
> will block netperf when it tries to send faster than the link.  Others 
> do not.
>