This attribute specifies the maximum number of Frame Relay calls
of any type (PVC, SPVC, or SVC) which can be simultaneously
'current' on this LP. Note that 'current' doesn't necessarily mean
that the call is in data transfer. It minimally means that such a call
can subsequently generate accounting records. When the value of
currentCalls reaches the value of maxCalls for FR on this LP,
subsequent call attempts are rejected by the FR services.