8.2.4.6.5.2. Latency & Jitter Distribution
8.2.4.6.5.2.1. Enable/Disable
Control whether this impairment distribution is enabled.
Note
This command is not applicable for PE_BANDPOLICER and PE_BANDSHAPER because they have a separate ON / OFF parameter.
Corresponding low-level API class: PED_ENABLE
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.enable.set(action=enums.OnOff.ON)
await flow.impairment_distribution.latency_jitter_type_config.enable.set_on()
await flow.impairment_distribution.latency_jitter_type_config.enable.set(action=enums.OnOff.OFF)
await flow.impairment_distribution.latency_jitter_type_config.enable.set_off()
resp = await flow.impairment_distribution.latency_jitter_type_config.off.get()
resp.action
8.2.4.6.5.2.2. Off Distribution
Configure Impairments Distribution to OFF. Assigning a different distribution than OFF to an impairment will activate the impairment. To de-activate the impairment assign distribution OFF.
Corresponding low-level API class: PED_OFF
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.off.set()
resp = await flow.impairment_distribution.latency_jitter_type_config.off.get()
resp.action
8.2.4.6.5.2.3. Constant
Configuration of Constant Delay distribution (DELAY only). Unit is ns (must be multiples of 100ns). Default value: Minimum supported per speed and FEC mode.
Note
If the latency is less than minimum latency, value is set to minimum latency. If the latency is greater than maximum latency, value is set to maximum latency.
Corresponding low-level API class: PED_CONST
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.constant_delay.set(delay=100)
resp = await flow.impairment_distribution.latency_jitter_type_config.constant_delay.get()
resp.delay
8.2.4.6.5.2.4. Accumulative Burst Distribution
Configuration of Accumulate & Burst distribution (DELAY only).
Note
If the delay is less than minimum latency, value is set to minimum latency. If the delay is greater than maximum latency, value is set to maximum latency.
Corresponding low-level API class: PED_ACCBURST
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.accumulate_and_burst.set(delay=1300)
resp = await flow.impairment_distribution.latency_jitter_type_config.accumulate_and_burst.get()
resp.delay
8.2.4.6.5.2.5. Step Distribution
Configuration of Step distribution (DELAY only).
Note
If the low/high is less than minimum latency, value is set to minimum latency. If the low/high is greater than maximum latency, value is set to maximum latency.
Corresponding low-level API class: PED_STEP
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.step.set(low=1300, high=77000)
resp = await flow.impairment_distribution.latency_jitter_type_config.step.get()
resp.low
resp.high
8.2.4.6.5.2.6. Uniform Distribution
Configuration of Uniform distribution.
Note
If minimum is less than minimum, value is set to minimum. If minimum is greater than maximum, value is set to maximum.
Corresponding low-level API class: PED_UNI
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.uniform.set(minimum=1, maximum=1)
resp = await flow.impairment_distribution.latency_jitter_type_config.uniform.get()
resp.minimum
resp.maximum
8.2.4.6.5.2.7. Gaussian Distribution
Configuration of Gaussian distribution.
Note
- In case of
_impairment_type_xindex != DELAY: mean plus 3 times standard deviation should be less than or equal to max allowed (4194288).
mean should always be at least 3 times the standard deviation, this to ensure that the impairment distance is always positive.
- In case of
_impairment_type_xindex = DELAY: mean plus 3 times standard deviation should be less than or equal to the maximum latency.
mean minus 3 times the standard deviation should be greater than or equal to minimum latency.
Corresponding low-level API class: PED_GAUSS
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.gaussian.set(mean=1, std_deviation=1)
resp = await flow.impairment_distribution.latency_jitter_type_config.gaussian.get()
resp.mean
resp.std_deviation
8.2.4.6.5.2.8. Poisson Distribution
Configuration of “Poisson” distribution.
Note
Standard deviation is derived from mean, i.e., standard deviation = SQRT(mean).
In case of _impairment_type_xindex != DELAY, mean plus 3 times standard deviation should be less than or equal to max allowed (4194288).
In case of _impairment_type_xindex = DELAY, mean plus 3 times standard deviation should be less than or equal to the maximum latency.
Corresponding low-level API class: PED_POISSON
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.poisson.set(mean=100)
resp = await flow.impairment_distribution.latency_jitter_type_config.poisson.get()
resp.mean
8.2.4.6.5.2.9. Gamma Distribution
Configuration of Gamma distribution.
Note
Mean and Standard deviation are calculated from Shape and Scale parameters and validation is performed using those. standard deviation = [SQRT(shape * scale * scale)]mean = [shape * scale].
In case of _impairment_type_xindex != DELAY,
(1) mean plus 4 times standard deviation should be less than or equal to max allowed(4194288).
(2)shape and scale should be greater than or equal to 0.
In case of _impairment_type_xindex = DELAY, mean plus 4 times standard deviation should be less than or equal to the maximum latency.
Corresponding low-level API class: PED_GAMMA
flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.latency_jitter_type_config.gamma.set(shape=1, scale=1)
resp = await flow.impairment_distribution.latency_jitter_type_config.gamma.get()
resp.shape
resp.scale
8.2.4.6.5.2.10. Custom Distribution
Associate a custom distribution to a flow and impairment type.
Note
Before associating a custom distribution, the below validation checks are applied.
In case of _impairment_type_xindex != DELAY,
(1) Custom values should be less than or equal to max allowed (4194288).
(2) Custom distribution bust contain 512 values.
In case of _impairment_type_xindex = DELAY,
(1) Custom values should be less than or equal to the maximum latency.
(2) Custom values should be greater than or equal to minimum latency.
(3) Custom distribution should contain 1024 values.
Corresponding low-level API class: PED_CUST
# Custom distribution for impairment Corruption
flow = port.emulation.flows[1] # e.g. flow_id = 1
data_x=[0, 1] * 256
await port.custom_distributions.assign(0)
await port.custom_distributions[0].comment.set(comment="Example Custom Distribution")
await port.custom_distributions[0].definition.set(linear=enums.OnOff.OFF, symmetric=enums.OnOff.OFF, entry_count=len(data_x), data_x=data_x)
await flow.impairment_distribution.latency_jitter_type_config.custom.set(cust_id=0)
resp = await flow.impairment_distribution.latency_jitter_type_config.custom.get()
resp.cust_id