This read-only Integer32 (0..248) describes the number of DS0s available for new connections on VISM, updated by the VISM firmware after each connection setup. This is the card-wide analog of vismFreeDs0Count and gives an admin a live view of remaining call capacity as connections are made and torn down. For example, an admin monitoring for capacity exhaustion during a high-traffic event would watch vismAvailableDs0Count trend toward zero as an early warning to add capacity or throttle new calls.