perfSONAR User Q&A and Other Discussion

[John Mann <>]

Hi,

The iperf3 shows retransmits in 3 out of the 20 seconds,

and throughput seems unaffected at those retransmit times.

I would suspect the firewall.

"2 Gbit/s" might be marketing-speak for 1 Gbit/s in both directions.

The firewall may be built out of several processing elements, each of which can handle 1 Gbit/s of traffic.

Fine for aggregated commodity network traffic, but not good id you need a tiny number of very large flows.

This idea is supported by "4 parallel streams, it goes up to 3.7Gbps".

See, for example:

fasterdata.es.net/science-dmz/science-dmz-security/

www.internet2.edu/presentations/tip2013/20130115-dart-science-dmz.pdf

Thanks,

    John

On 3 May 2014 07:15, Brian Tierney <> wrote:

On Fri, May 2, 2014 at 2:10 PM, Alan Whinery <> wrote:
> Brian  T. - Yes, he said there was a firewall.

Sorry, I forgot.

Brian K: when you say:

"core router --> firewall (10G) (fw throughput = 2G)"

Where is the number "2G" from?  Since you are seeing a large number of
retransmits, I dont think you'll be able to get to 2G.

>
> Brian Koch,
>
> If NDT is enabled as a service on the target host, can you do
>
> web100clt -l -n <targethost>
>
> and send the results?
>
> Note: if you are sanitizing, the IP target's name or IP appears once in
> the output.
>
>
>
> On 5/2/2014 11:04 AM, Brian Tierney wrote:
>> With 909 retransmits, you will never get much about 1Gbps.
>>
>> How "full" is that path? Is there a firewall on the path? Also look at
>> errors on all your router / switch interfaces.
>> There may be a dirty fiber.
>>
>>
>>
>>
>> On Fri, May 2, 2014 at 1:52 PM, Koch, Brian <> wrote:
>>> Latency shows ~0.7ms with 0% loss.
>>>
>>> -----Original Message-----
>>> From: Brian Tierney [mailto:]
>>> Sent: Friday, May 02, 2014 3:35 PM
>>> Cc: Koch, Brian;
>>> Subject: Re: [perfsonar-user] bwctl speed questions
>>>
>>> Brian: What latency is the path you are testing? Does owamp show any packet loss on that path?
>>>
>>> Try doing a test with iperf3, which will give you TCP retransmit  count.
>>>
>>> bwctl -c hostname -I iperf3 -i1 -fm -x -t20
>>>
>>>
>>>
>>>
>>> On Fri, May 2, 2014 at 7:47 AM, Aaron Brown <> wrote:
>>>> Hey Brian,
>>>>
>>>> Unfortunately, there’s not a way to do multiple streams currently. The idea was to show how single stream performance looked since any network can be made to look good with enough streams :) The next version of the Toolkit should include the ability to configure number of streams, however.
>>>>
>>>> Cheers,
>>>> Aaron
>>>>
>>>> On May 2, 2014, at 10:04 AM, wrote:
>>>>
>>>>> Is there a way to run multiple data streams? I'm not sure why the
>>>>> data path is fully tested.
>>>>> Connections:
>>>>> Perfsonar --> core router (10G)
>>>>> core router --> firewall (10G) (fw throughput = 2G) firewall -->
>>>>> outside WAN router (10G) outside WAN router --> perfsonar (10G)
>>>>>
>>>>> Theoretically, I should be seeing close to 2Gbps on my bwctl graphs,
>>>>> but graphs are barely showing over 1Gbps.
>>>>>
>>>>> Are there some settings I need to tweak? I'm a little new to this.
>>>
>>>
>>> --
>>> Brian Tierney, http://www.es.net/tierney
>>>
>>> Energy Sciences Network (ESnet), Berkeley National Lab
>>>
>>> http://fasterdata.es.net
>>
>>
>



--
Brian Tierney, http://www.es.net/tierney

Energy Sciences Network (ESnet), Berkeley National Lab

http://fasterdata.es.net