Arris TM822G is one of the best Comcast approved modems with telephony. No router built in. Bought ours new on Amazon. Be careful buying used modems that have been previously registered/activated to someone else. Comcast may refuse to activate them.
Always check first with Comcast to make sure the Model modem you want to purchase is compatible.
Arris MODEL: TM822G
ARRIS DOCSIS 3.0 / PacketCable 2.0 Touchstone Telephony Modem
HW_REV: 2
VENDOR: Arris Interactive, L.L.C.
To see the Comcast cable Modems status, event logs, version, power levels, downstream upstream levels etc.
Open your computer's Internet browser
Enter "192.168.100.1" in the URL box of the browser. Click Enter.