Intermittent Connectivity

I've been having intermittent connectivity for the past few weeks.  When I call/chat w/ Cox I'm told all is well w/ the service at large and to either unplug/replug router or they send me a signal which resolves the issue.  Considering this is a recurring issue I'm not satisfied w/ having to manually bump the router or call them every time there is an issue.  Yesterday, we lost connectivity, got busy w/ other things, did nothing to the router and the issue resolved itself.  I'm thinking it's something w/ the inbound signal and not my devices but am open to suggestions.  Things I've done to date:

- replaced cable splitter

- confirmed firmware w/ wifi router (Apple Airport Extreme) is current

- attempted to verify that firmware on Cisco DPC3010 router is current but Cox representative couldn't/wouldn't confirm

We are an Apple family and working on MacBook Pro's.  

Thoughts?