Specifies the number of bytes by which each subsequent ping packet is incremented. The step amount can be any number from 0 (which leaves the ping size constant) up to (2^32 - 1). Note that after adding the step amount to the current ping size, if this is greater than the end size, then the current size will be wrapped around to the start size. If you want to send ping packets of the same size every time, set the start and end size to be equal, and the step amount to be 0. To do a sweeping ping of every packet size, set start to 64, end to 1518, and step amount to 1. You can set step amount to -1 to sweep in the other direction. This object may be changed while a ping is in progress.