Me too (re: voice drops). I hadn't noticed a 20-second regularity, but I'll look for it now.
For me, several minutes into the call the drops begin and never stop. I lose 20-30% of ev_y _entence being spo__ for as _ong as I c_ stand _t. The other party hears me fine. But I'm missing 20-30% of the audio on my end. Nowadays I just immediately apologize, hang up, and call again on some other (non-Comcast) phone. Happens 2-3 times a day, at least. I know it's Comcast, and I know it's not my household equipment, because I am text-chatting other people during the call and everyone else is getting flawless audio except for one -- another Comcast phone customer in my community.
It would be great if someone from Comcast would comment here.
BTW I guessed it was due to dropped/garbled network packets.
