Some things you can try here.
Many times these measures will resolve a lot of intermittent issues.
My top suspect in these scenarios is usually P2P applications, running, they can bring a lot of routers to their knees.
- For wireless connections, change the channel on the router, I like channels 1, 6, and 11 in the US.
- Update the firmware to the latest version available on the manufacturer's site.
- Reset the router to factory defaults and reconfigure.
Many times these measures will resolve a lot of intermittent issues.
My top suspect in these scenarios is usually P2P applications, running, they can bring a lot of routers to their knees.