Cisco EPC3925 User Manual page 53

Section
4021192 Rev B
Field Description
No ACK
Allows you to enable or disable NO ACK. This feature is
recommended for data services where transmission is
important and packet loss is tolerable to a certain degree. If
you select Disable, an acknowledge packet is returned for
every packet received. This provides a more reliable
transmission, but it increases traffic load, which decreases
performance.
Select the desired option:

Enable

Disable (factory default)
Configure Wireless Settings
53