This attribute indicates the current available aggregate CIR reported
to the hunt group in the Availability Message Packet (AMP). It is
incremented by the application when a DLCI is freed. It is
decremented when a DLCI is allocated. The value is the sum of the
currently available aggregate CIRs for SVCs.
Both this attribute and the availableDlcis attribute must be non zero
for this DNA to receive calls on the hunt group.