When the atc tell me to descend, it must be done immediately otherwise the controller continuously says:You have busted your altitude, your assigned altitude is fl:---.But the A320 doesn't descend immediately,it takes about 20 or 30 seconds to do it because it has to reduce the speed, usually from 300 Kias to 260Kias.I can push the button 'exped', but the rate of descend is too much high!

One of your descents should offer the option "when ready descend to . . .", usually your first descent from cruise.One thing you can do is not acknowledge the command until the aircraft starts descending. You may get "I say again" but that takes quite a while. Be aware that delaying an acknowledgment may cause you to miss a waypoint credit if you pass it while RC is waiting for your ack.From your description of AIS if you are in the approach phase try flying under the arrival NOTAMS option.Version 5 will have more tolerance but that is a very long time away from release.

if you have auto reply on, turn it off, manually ack when you are descendingif the rc co-pilot has the comms, he's going to answer right away :-(jd