D-Link DWR-921 
You can apply this procedure on computer, PlayStation, XBOX, Nintendo and any other gaming device  
 
PlayStation 4 
In order to solve your PS4 problem please follow the below steps 
  Step 1: Firstly navigate to the settings menu on your PS4  
  Step 2: Next select Network 
  Step 3: You need to select “set up internet connection” 
  Step 4: You need to select “custom” 
  Step 5: You need now to select the method in which your PS4 connects to the internet 
  Step 6: Make sure to set your IP address  manually  
  Step 7: Enter the desired IP address that you would like to use for your PlayStation®4.   
 IP Address: 192.168.0.50 
 Subnet Mask: 255.255.255.0 
 Default Router: 192.168.0.1 (IP Address of your router) 
 Primary DNS: 193.227.177.130 
 Secondary DNS: 194.126.16.38 
  Step 8: In MTU Settings, select automatic. 
  Step 9: In Proxy servers , select Do Not Use  
  Step 10: Select TEST Internet Connection. 
  Step 11: Connect a device to your D-Link router (using cable / WIFI) 
  Step 12: In your browser enter the address 192.168.0.1 
  Step 13: You will be prompted to enter Username: admin and Password: admin or keep it blank 
  Step 14: Click Advanced then DMZ 
  Step 15: Make sure DMZ is enabled ,and type in DMZ IP Address  192.168.0.50 then click Apply