Você pode instalar um firmware diferente, como o DD-WRT , para que seu modem permita que você faça algo semelhante.
A ativação da QoS usando algo como este guia deve ser suficiente para o que você deseja fazer .
Esta é uma cópia e colagem do que o guia diz para a configuração inicial, mas você deve sempre consultar a documentação para certificar-se de que eles não foram atualizados desde o copiar e colar.
Log into the Web Interface
Select the NAT/QoS tab and then the QoS sub-tab.
Click "Enable"
Set Port to "WAN". The term WAN here refers to the WAN connection on your router while
the term "LAN & WLAN" refers to the combination of your local ports and Wifi
connections. Selecting "WAN" will apply QoS only to traffic moving into or out of your
network, while selecting "LAN & WLAN" will apply QoS to ALL traffic passing through
the router on your network. Selecting "LAN & WLAN" will limit WLAN<->WLAN and
LAN<->WLAN transfer speeds to the lowest of the uplink/downlink speeds that you set
while also limiting the LAN & WLAN<->WAN rates, and thus will not be the preferred
solution for most people.
Select HFSC as your packet scheduler.
Select FQ_CODEL as your queueing discipline.
Set your upload and download speeds. You can use a speed test like Speedtest.net to
check your actual connection speed. Some ISPs also provide their own bandwidth testing
service, which may be more reliable than the links provided. Enter no higher than
90% of the values you measured into the proper fields. After you have everything set
run the speed test again. If you get near 90% of your previous measurement in each
direction then things are cool. If you get results which are way off then chances
are that you have reversed these values. You must enter a value for the uplink field
but if you want you can enter 0 for the downlink field in which case no QoS will occur
in that direction though setting your downlink field to 0 isn't recommended.