A username and password are required to access the router admin panel. Usernames and passwords are often forgotten. If you can not log in, you do not have to panic. In such a situation there are couple of things you can do:
Default Username and Password
The user guide that came with your device typically includes a default username and password. If it is not possible to find this information, you can find the username and password of your device listed below.
Reset Router to Factory Settings
If you are not able to log in with the usernames and passwords in the user manual or above, you need to reset your device. When you reset your router, all the settings will be reset to factory defaults, so your username and password will also be reset. Hold the reset button on the back of the device for 10-15 seconds with a needle or a toothpick. You can then log in to the admin panel using the username and password in the factory settings.

Forward Ports Without a Password
If you have experimented with a variety of options, and you still cannot recover the router user and password, you can employ the use of Universal Plug and Play (UPnP), which would allow you to forward ports, and it would exempt the requirement of having a password to access your internet connection. A majority of the routers are designed to enable external applications to access ports through the router. If you are using an UPnP-enabled router, it would allow you to access the required ports. In addition, you can administer the use of UPnP PortMapper to forward the ports of your preference.