I'm not sure where to find that in my router. I'm using a Cisco DPC3825 DOCSIS 3.0 Data Gateway
I found this section in settings:
Wireless Tab / QoS
The Quality of Service (QoS) settings allow you to specify priorities for different types of traffic. Lower priority traffic will be slowed down to allow greater throughput or less delay for high priority traffic.
Wireless
Wi-Fi Multimedia (WMM) support is enabled by default. If WMM is also supported by your wireless clients, then voice and multimedia traffic will be given higher priority than other traffic.
Select the desired option:
Enable
Disable
No ACK is disabled by default. This setting is recommended for voice, for which speed of 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. If WMM is disabled then this setting has no effect, and you can not disable ACKs from being returned from the stations.
Select the desired option:
Enable
Disable
Click the Save Settings button to apply your changes or the Cancel Changes button to cancel.