Are your router and the phone base on the same electrical circuit? If so, there might be RF interference being transmitted to the router power supply or the FIOS 'modem'. This can be eliminated by using a good quality power strip with an RF filter for the router and modem.
I think I've gotten the issue 'fixed' but I don't know what other kinds of issues I could have caused.
I've got a linksys dual band router plugged into the FIOS cable modem; In the setup for the cable modem, I switched the "wireless mode" to "Performance Mode(802.11n)" rather than it's former "Compatibility Mode" setting. This caused my computer to be unable to connect to the connection from the cable modem itself, but upon connectiong to the connection from the Linksys router, it seems to work without the interruption.
I'm assuming I should be okay now as long as I connect everything through the connection running off the linksys router rather than the cable modem?
I disabled the wifi on my cable modem and I'm just using a linksys e2500 dual band router.
I separated the 5gz and 2.5 ghz connections, and i've tried both at this point on various channels, with the same results - if i'm playing a game I'll have great ping (30ms) and if i make a phone call, it is fine, but once i hang up the connection is briefly interrupted.