Drop 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 CLI command: PED_ENABLE

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.enable.set(action=enums.OnOff.ON)
await flow.impairment_distribution.drop_type_config.enable.set_on()
await flow.impairment_distribution.drop_type_config.enable.set(action=enums.OnOff.OFF)
await flow.impairment_distribution.drop_type_config.enable.set_off()

resp = await flow.impairment_distribution.drop_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 CLI command: PED_OFF

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.off.set()

resp = await flow.impairment_distribution.drop_type_config.off.get()
resp.action

Fixed Rate Distribution

Configuration of Fixed Rate distribution. This is predictable distribution with nearly equal distance between impairments, to match the configured probability.

Note

In case of misordering, a special limit applies, probability * (depth + 1) should be less than 1000000.

Corresponding CLI command: PED_FIXED

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.fixed_rate.set(probability=10_000)

resp = await flow.impairment_distribution.drop_type_config.fixed_rate.get()
resp.probability

Random Rate Distribution

Configuration of Random Rate distribution. Packets are impaired randomly based on a per packet probability. This way the impaired fraction of packets will be equal to the configured probability over time. Random probability in ppm (i.e. 1 means 0.0001%)

Corresponding CLI command: PED_RANDOM

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.random_rate.set(probability=10_000)

resp = await flow.impairment_distribution.drop_type_config.random_rate.get()
resp.probability

Bit Error Rate Distribution

Configuration of Bit Error Rate distribution.

Corresponding CLI command: PED_BER

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.bit_error_rate.set(coef=1, exp=1)

resp = await flow.impairment_distribution.drop_type_config.bit_error_rate.get()
resp.coef
resp.exp

Fixed Burst Distribution

Configuration of Fixed Burst distribution.

Corresponding CLI command: PED_FIXEDBURST

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.fixed_burst.set(burst_size=1300)

resp = await flow.impairment_distribution.drop_type_config.fixed_burst.get()
resp.burst_size

Random Burst Distribution

Configuration of Random Burst distribution.

Corresponding CLI command: PED_RANDOMBURST

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.random_burst.set(minimum=1, maximum=10, probability=10_000)

resp = await flow.impairment_distribution.drop_type_config.random_burst.get()
resp.minimum
resp.maximum
resp.probability

Gilbert Elliott Distribution

Configuration of Gilbert-Elliot distribution.

Corresponding CLI command: PED_GE

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.ge.set(good_state_prob=0, good_state_trans_prob=0, bad_state_prob=0, bad_state_trans_prob=0)

resp = await flow.impairment_distribution.drop_type_config.ge.get()
resp.good_state_prob
resp.good_state_trans_prob
resp.bad_state_prob
resp.bad_state_trans_prob

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 CLI command: PED_UNI

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.uniform.set(minimum=1, maximum=1)

resp = await flow.impairment_distribution.drop_type_config.uniform.get()
resp.minimum
resp.maximum

Gaussian Distribution

Configuration of Gaussian distribution.

Note

In case of _impairment_type_xindex != DELAY:

1. mean plus 3 times standard deviation should be less than or equal to max allowed (4194288).

2. 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:

1. mean plus 3 times standard deviation should be less than or equal to the maximum latency.

2. mean minus 3 times the standard deviation should be greater than or equal to minimum latency.

Corresponding CLI command: PED_GAUSS

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.gaussian.set(mean=1, std_deviation=1)

resp = await flow.impairment_distribution.drop_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 CLI command: PED_POISSON

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.poisson.set(mean=100)

resp = await flow.impairment_distribution.drop_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 CLI command: PED_GAMMA

flow = port.emulation.flows[1] # e.g. flow_id = 1
await flow.impairment_distribution.drop_type_config.gamma.set(shape=1, scale=1)

resp = await flow.impairment_distribution.drop_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 CLI command: 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.drop_type_config.custom.set(cust_id=0)

resp = await flow.impairment_distribution.drop_type_config.custom.get()
resp.cust_id