Latency & Jitter Distribution

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

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

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

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

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

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

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

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

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

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