We have been with RCN since we moved to Chicago. It has been nothing but a nightmare. We pay for 20 Mbs and most of the time get 2 or 3. We have the bundle and have had to constantly call tech support to see about getting this issue resolved. When they had to install another modem to get us the 20 Mbs we are paying for they totally messed up the account and charged us for the modem and almost quadrupled our bill. They still have not got it straight yet and we still don't have the 20 Mbs download.
You can get a Docsis 3.0 modem at a decent price! Motorola and Zoom sell them. Don't rent a modem, its a pure old cash cow. They rent out old models.
I had RCN too and had problems with them sometimes too, especially Internet.
The best you can do to relieve this situation is to get a back up connection (ATT DSL - which is cheap now) or 4G (Wimax) from Clear.
Just make sure you get a dual wan router or if you get another wireless router for wi-fi connection make sure they do not overlap on the same channel. The non-overlaping channels are 1,6,11m (talking about g standard, dunno about n).
You can always go with a long twisted pair Ethernet cable
You probably don't have too if they have a voip adapter . The way it works is this:
cable modem--> voip adapter + phone --> gateway (router)--> pcs
you must likely use gateway with built-in voip, modem and router.
I only use cell phone and never used VOIP so I have no exact idea. Where I lived and live now coverage has been always good both inside and outside. Now with 3G microcells less people depend on voip or pots (traditional)