fhendrikx / wansim

WANsim allows you to emulate a WAN connection
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Varying the Bandwidth Setting Does Not Appear to Affect Throughput #2

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
What steps will reproduce the problem?
1. From the CLI, type 'b' and change WAN Bandwidth to 500000
2. Run an iPerf test through the WANsim box -- with my gear, I'm seeing
   ~350Mb/s
3. Change WAN Bandwidth to 10000
4. Run an iPerf test through the WANsim box -- I still see ~350Mb/s

What is the expected output? What do you see instead?
- The first iPerf result fits my expectations -- given my gear, ~1/3 
  of a GigE pipe seems reasonable.  But the second result surprises me --
  I would have expected iPerf to deliver results close to 10Mb/s, since 
  I set WAN Bandwidth to 10 Mb/s

- I have repeated these results with WAN Bandwidth settings of 50000 and 
  100000.  I attach charts illustrating these results.

What version of the product are you using? On what operating system?
- WANsim 2.0.1-1 running under Ubuntu Server 14.04.1 LTS on a PC Engines 
  apu1c board.

Please provide any additional information below.

Original issue reported on code.google.com by stuart.k...@gmail.com on 9 Sep 2014 at 12:30

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GoogleCodeExporter commented 9 years ago
I notice this too. The changes in the settings did not work before I did a 
"save [s]" and "restart [r]" from the menu list. I did not test for the 
bandwidth change, but for delay and loss it needed the save/restart before.
It kind of make sense that the configuration is read on restart and therefore a 
save is necessary. It is worth a try.

Original comment by stef...@sphere.dk on 3 Nov 2014 at 8:56

GoogleCodeExporter commented 9 years ago
We've been debugging this issue with Stuart. It looks like it may relate to the 
kernel version that is installed... But a definitive reason is not yet clear.

Original comment by ferry.he...@gmail.com on 3 Nov 2014 at 9:14

GoogleCodeExporter commented 9 years ago

Please use the latest release (2.1.0)

Please try setting GRO off for your interfaces.

Original comment by ferry.he...@gmail.com on 11 Nov 2014 at 11:08