mscVctDnaHgMAvailableChannels 1.3.6.1.4.1.562.36.2.1.5130.2.3.11.1.2

This attribute indicates the number of available channels reported to the hunt group in the Availability Message Packet (AMP). It is modified by adding 1 by the application when a channel is freed and subtracting 1 when a channel is occupied.