A significant source of delay in a structured service is the
amount of time it takes to collect enough data to fill a cell.
This period of time can be reduced by sending cells that
are only partially filled with data (idlePattern octets are
added to the ATM payload beyond the partial fill level).
This attribute defines the number of payload octets to fill
with data. It is applicable to structured services only, and
must be set to 47 for unstructured services.
On a given AAL1 Function Processor, the maximum cell
rate that can be sustained is dependent upon the combined
bandwidths of the provisioned services, and (for structured
services) the levels of partialFill. The smaller the
partialFill level, the greater the cell rate and hence the
fewer the services that can be sustained at that fill level.