burst mode

[bmah888]

From bltierney on July 16, 2009 10:38:15

The 'burst mode' in the new version of nuttcp sounds useful.

Here is the description from Chris Tracy:

"nuttcp has a new option that allows you
to specify that traffic is sent in bursts, instead of a nice smooth
transfer. This is extremely useful in determining if a switch has
enough buffering to handle a 10GigE -> GigE translation (e.g. in
general, most cheaper 1U switches cannot handle this, while bigger
modular switches do have the buffering to handle it). I recently ran
into this issue when sending from a host with a 10GigE NIC using a
bursty application (UltraGrid) and I ended up with 250Mbps (averaged
but extremely bursty) going into a 10GigE port on a 1U switch and only
80Mbps coming out of the GigE port. iperf/nuttcp in standard rate
limit mode set to 250Mbps did not trigger the problem, but nuttcp's
new burst testing mode will reproduce the buffering issue."

See the code at: ftp://ftp.lcp.nrl.navy.mil/u/bill/private/nuttcp-6.3.1-beta2.c to see how
this is implemented.

Original issue: http://code.google.com/p/iperf/issues/detail?id=3

[bmah888]

From jdugan.esnet on December 09, 2009 22:54:07

Labels: Priority-Medium Milestone-3.1a1

[bmah888]

From bltierney@es.net on March 12, 2013 15:47:02

Owner: japoskanzer@lbl.gov

[bmah888]

From bltierney@es.net on November 08, 2013 15:34:09

nuttcp does this with the following argument:

e.g.: Send 300 Mbps of UDP in bursts of 20 packets for 5 seconds

./nuttcp -u -Ri300m/20 -i 1 -T5 nettest.lbl.gov

[bmah888]

From jef.poskanzer on December 17, 2013 16:17:18

Implemented!

[bmah888]

From bltierney@es.net on December 18, 2013 13:06:06

-h flag should be updated too

[bmah888]

From bltierney@es.net on December 18, 2013 14:21:06

Labels: -Milestone-3.1a1 Milestone-3.0-Release

[bmah888]

From jef.poskanzer on December 18, 2013 20:57:33

Updated the -h output too.

Status: Fixed