question

bbaker avatar image
bbaker asked bbaker posted

STC GUI Stream Load

Hi,

 

I'm trying to set up two data streams using STC GUI.  I'm running into a problem where I configure the LoadUnit for "KILOBITS_PER_SECOND" but the actual data rate is much higher.  Is there some option I am not properly setting that is keeping the LoadUnit option from being applied?

 

Here are the settings for the two streams:

 

 

StreamBlock

Active                           : true
AllowInvalidHeaders              : false
BurstSize                        : 1
ConstantFillPattern              : 0
Destination                      : Device 1
EnableBidirectionalTraffic       : false
EnableControlPlane               : false
EnableFcsErrorInsertion          : false
EnableStreamOnlyGeneration       : true
EnableTxPortSendingTrafficToSelf : false
EndpointMapping                  : ONE_TO_ONE
FillType                         : CONSTANT
FixedFrameLength                 : 128
FrameLengthMode                  : FIXED
Id                               : 1
InsertSig                        : true
InterFrameGap                    : 12
Load                             : 1.0
LoadMode                         : FIXED
LoadUnit                         : KILOBITS_PER_SECOND
MaxFrameLength                   : 256
MinFrameLength                   : 128
Name                             : RemoteToHost
Port                             : 1
Priority                         : 0
RxPorts                          : 
Source                           : Device 1
StartDelay                       : 0
StepFrameLength                  : 1
TrafficPattern                   : PAIR


StreamBlock

Active                           : true
AllowInvalidHeaders              : false
BurstSize                        : 1
ConstantFillPattern              : 0
Destination                      : Device 1
EnableBidirectionalTraffic       : false
EnableControlPlane               : false
EnableFcsErrorInsertion          : false
EnableStreamOnlyGeneration       : true
EnableTxPortSendingTrafficToSelf : false
EndpointMapping                  : ONE_TO_ONE
FillType                         : CONSTANT
FixedFrameLength                 : 128
FrameLengthMode                  : FIXED
Id                               : 1
InsertSig                        : true
InterFrameGap                    : 12
Load                             : 1.0
LoadMode                         : FIXED
LoadUnit                         : KILOBITS_PER_SECOND
MaxFrameLength                   : 256
MinFrameLength                   : 128
Name                             : HostToRemote
Port                             : 2
Priority                         : 0
RxPorts                          : 
Source                           : Device 1
StartDelay                       : 0
StepFrameLength                  : 1
TrafficPattern                   : PAIR

 

 

Note in the above settings that "Load" is set to 1.0 and "LoadUnit" is set to KILOBITS_PER_SECOND.  I was expecting this to generate a stream of 128 byte packets at 1Kbps.  However, it appears the rate is much higher.  See the GeneratorBitRate in the below output:

 

 

showStats: GeneratorPortResults

Port  CounterTimestamp  GeneratorAbortFrameCount  GeneratorAbortFrameRate  GeneratorBitRate  
---------------------------------------------------------------------------------------------
1     0                 0                         0                        86486392          
2     0                 0                         0                        86486232

 

 

iTesttraffic generation
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VidyaH avatar image
VidyaH answered VidyaH posted

Hi,

Could you please load the same configuration in actual STC application and see if you are still getting the similar rate? I tried with the similar streamblocks as per your configuration and generater rates seems to be fine. I would verify the "All Traffic Generators" section in Spirent test center configuration  to see if all configuration is same as you expected?

 

Thanks,

Vidya

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bbaker avatar image bbaker commented ·

I can configure this in the STC Application and it works fine.  However, I am not using STC Application config files in iTest.  I am configuring the STC GUI using only data gathered from my Topology file.  That's why I was wondering if there is some option I may have missed that prevents the LoadUnit option from being applied.

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VidyaH avatar image VidyaH bbaker commented ·

Hi,

Can you check if the "LoadUnit" in "All Traffic Generators" are showing the "Kilobits_per_second" as shown in screenshot.

 

Thanks,

Vidya

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bbaker avatar image bbaker VidyaH commented ·

Interesting...

 

Looking at "All Traffic Generators" is shows the LoadUnit as PERCENT_LINE_RATE for each of my two streams.  However, looking at "Traffic Generator" located under each port, it has the LoadUnit correctly set at KILOBITS_PER_SECOND".

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VidyaH avatar image VidyaH bbaker commented ·

By default, LoadUnit for traffic generators are "PERCENT_LINE_RATE". You can change it to your specific unit by clicking on "Port Load" in traffic generator section as shown in screenshot. After selecting kbps , click on "Apply" button to configure the changes. After this, please verify the generator rates to see if it works fine?

 

Hope this helps.

 

Thanks,

Vidya

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bbaker avatar image bbaker VidyaH commented ·

Vidya,

 

Reconfiguring the Port Load on the Traffic Generator works.  This led me to find a work around for the problem.

 

I was setting the value for Load and LoadUnit in the addStreamBlock command.  I have now added the configureGenerator command to set these values a second time which has fixed the problem.

 

It looks like there may be a bug in the addSteamBlock command where the Load and LoadUnit values are not fully applied.  They appear correct when you look at the individual Traffic Generator settings for each port, but they are incorrect when looking at them under All Traffic Generators.

 

Thanks for your help!

 

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VidyaH avatar image VidyaH bbaker commented ·

I agree. We can improve in this case.I will log an issue.

 

Thanks,

Vidya

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