The maximum simultaneous calls is 6.

The rollout across the fleet has been very slow so far. You will know that your aircraft has it because a video will be played in the climbout introducing the service, and if your phone is compatible, you'll get a welcome text message telling you about service availability. You can also tell the aircraft has the system installed by the small panel to the left of the L1 door, that looks like the front of a cellphone imbedded into the wall. That's what the purser uses to control the system.