No charge for the two-way video time.

FORBES: Yes, I Wear SpongeBob Boxer Shorts. That's Why I'll Pass On Video Technology For Now

Whereas traditional systems require the use of one or two dedicated channels per user every time there is a two-way communications, trunked systems automatically select the voice channel that a user may talk on every time he transmits.

FORBES: Free Speech v. Denial Of Communications For Public Safety Agencies?

The truth is that CableCARDs have been capable of authorizing two-way communications for some time, but there wasn't a way for 3rd party cable devices to be certified by CableLabs -- like the latest cable deployed STBs -- for two-way communication.

ENGADGET: Time Warner Cable deploys 150k OpenCable STBs, aka CableCARD 2.0