How to use Packet Loss settings

Hello,
I am evaluating this product and have a question about packet loss settings:

The packet loss Fixed Number option does not seem to work for me. When I select Fixed Number I cannot alter the values in From and To fields.
I can change these values when Percentage option is selected. If I select Percentage with values 1 to 5 and then select Fixed Number it displays the loss of every 1st packet.

Any help you can provide would be appreciated. Thanks.

With the packet loss, there are two options:

• percentage of packets to be lost. For example, you can specify 1% to be lost, and at the same time configure it as sequential loss.
  
  In this case, if the sequential loss is set from 1 to 1 packet, it means in each 1000 packets there will be about 10 lost packets, randomly distributed, 1 packet lost at a time.
  
  If the sequential loss is set from 2 to 4 packets, likewise it means in each 1000 packets there will be about 10 lost in total, but this time they will be lost in bursts of 2, 3 or 4 lost packets at a time. This closely resembles a physical connection that would usually have an unexpected loss of a few packets at once, e.g. due to interference.
• fixed number simply loses 1 packet out of each X (or every Xth packet). Sequential loss doesn't apply in this case.