This read-write value sets how many user data octets are packed into each ATM cell when partial cell fill is used, with 47 (a full cell's payload) meaning partial fill is disabled, and valid ranges narrowing depending on T1/E1 and structured/unstructured mode. An administrator uses partial fill below 47 to reduce packetization delay for delay-sensitive voice-like traffic, at the cost of lower payload efficiency per cell, while ensuring the value stays larger than the number of timeslots assigned to that channel. For example, setting cesPartialFill to 25 on a structured T1 channel reduces cell-fill delay compared to the default full 47-octet fill.