If wireless devices are no longer connected to the network, but hard wired computers, and VOIP phones are still functioning on the network. Re-enable wireless on the router.
On a desktop computer with network access, open a web browser.
In the address bar type in http://192.168.1.1 or whatever your routers IP address is. And log in with the username admin and password of password
On the home page you will see the wireless status as disabled, click on it to enable.
Click on Advanced tab on the top
Click on reboot
Your web browser screen will close with error page cannot be displayed
Wait a couple of minutes and test computers, phones, and wireless devices
