Most routers will work with VoIP, but some better than others. If you find that devices frequently disconnect and a need to reboot your router, it is probably time to change it.
We have found that TP-Link routers are well priced and perform well for VoIP. They also contain some diagnostic tools that can track usage by device for troubleshooting.
The TP Link C50 AC1200 is inexpensive and available from Amazon.ca