perfSONAR User Q&A and Other Discussion

[Louis-Berthier Soullière <>]

Hi and thanks Micheal, 

So, if I understand correctly :

packet-interval = time in seconds in between packet
packet-count = packet to send before reporting a result (600 by default in 
perfsonar)

PacketPerSec    =       Between packet (sec)    *       Count           =     
  Granularity in graph
10              =       0.1                     *       600             =     
  60 seconds
50              =       0.02                    *       600             =     
  12 seconds
100             =       0.01                    *       600             =     
  6 seconds
250             =       0.004                   *       600             =     
  2,4 seconds
500             =       0.002                   *       600             =     
  1,2 seconds
1000            =       0.001                   *       600             =     
  0,6 seconds

If the count could be modified in the interface, we could have the same 
granularity with less packet sent per seconds.

For less confusion, the interface could offer three input :

PacketPerSec    <x>     pps
Packet size     <y>     bytes
Granularity     <z>     sec

Greyed out for reference but dynamic with the value above (apply limit in 
function of the result ;  max packet or bandwidth)
Bandwitdh       <x*y*8/1000>    Mbps            
Count           <x*z>           packet

About the bandwidth, I don't understand why perfsonar assume 20 bytes as 
default. In powstream manual, the default padding is 0 Bytes.  If I enter 
20Bytes, no "-s" switch appear in pscheduler monitor. If I enter 40Bytes, -s 
20 appear.

The make things worst, even when excluding the control packet, the smallest 
packet in my wireshark capture is 66 bytes. (with 20 Bytes in perfsonar 
resulting in powstream task line in pscheduler monitor without "-s" switch.

From powstream manual : 

      -s size
              Size  of the padding to add to each minimally-sized test 
packet. The minimal size for a test packet in open mode is 14 bytes. The 
minimal
              size for a test packet in authenticated or encrypted mode is 32 
bytes.

              Default:
                     0 (bytes)

Thanks!

Louis-Berthier Soullière

-----Message d'origine-----
De : Michael Johnson [] 
Envoyé : 23 juillet 2019 15:47
À : Louis-Berthier Soullière <>
Cc : Andrew Lake <>; 
Objet : Re: [perfsonar-user] OWAMP Granularity

* PGP - S/MIME Signed by an unverified key: 2019-07-23 at 15:46:43

Hi,

"Packet rate" is simply the inverse of "packet interval" -- so, if you want 
0.1 seconds between packets, you would set "packet rate" to 10 packets per 
second.

I hope this is clear.

Thanks,
Michael

On Tue, Jul 23, 2019 at 02:08:00PM +0000, Louis-Berthier Soullière wrote:
>Hi Andrew,
>
>I'm using the web interface and I can only change :
>
>Packet Rate (packets per second) and Packet Size (bytes)
>
>I'm not using psconfig and I'm not familiar with it. (maybe I should 
>but I only have 2 console)
>
>It would be great to be able to modify the packet count in the web interface.
>
>Thanks
>
>Louis-Berthier Soullière
>
>De : Andrew Lake []
>Envoyé : 23 juillet 2019 09:13
>À : Louis-Berthier Soullière 
><>; 
> Objet : Re: [perfsonar-user] OWAMP 
>Granularity
>
>Hi,
>
>If you are talking command-line, the "pscheduler task latency” command 
>accepts a --packet-interval option sets the number of seconds between 
>packets (e.g. 0.1 = 10 packets per second) and the --packet-count option 
>indicates how many packets to send. For example, if you send 600 packets at 
>10 packets per second you will have a session that runs roughly 60 seconds 
>(which is the default). If a test is doing a 10 minute session, then someone 
>probably customized those two parameters. You can also use packet-interval 
>and packet-count parameters in the test spec of your psconfig file if you 
>want to adjust this for regular tests.
>
>Thanks,
>Andy
>
>
>On July 23, 2019 at 7:59:38 AM, Louis-Berthier Soullière 
>(<>)
> wrote:
>[cid:]
>Hi,
>
>I was wondering if it's possible to get a granularity finer than 600sec for 
>OWAMP.
>
>I've read something about OWPSAMPLECOUNT but I think it's a parameter that 
>goes back to bwctl.
>
>Any idea?
>
>Thanks!
>
>Louis-Berthier Soullière, CISSP
>Analyste en télécommunications, Exploitation du RITM
>
>Direction générale adjointe des opérations 
>technologiques<http://publications.msss.gouv.qc.ca/msss/fichiers/organi
>gramme/Visio-MSSS.pdf> Ministère de la Santé et des Services sociaux 
>3000, avenue St-Jean-Baptiste Québec (Québec) G2E 6J5
>418 527-5211, poste 5326
><>
>Extranet TI 
>RITM<http://extranet.ti.msss.rtss.qc.ca/Infrastructures/RITM/Accueil.as
>px>
>
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--
Michael Johnson
GlobalNOC DevOps Engineer


* Michael R Johnson <>
* Issuer: Internet2 - Unverified