The Allocated Cell Rate (specified in cells per second) for
traffic received on the interface for this Service Category.
This is the bandwidth allocated-to connections. For
CBR and VBR Service Categories, this value increases as a
result of connection setup and decreases as a result of
connection release. For ABR and UBR Service Categories,
this value changes as a result of connection setup
and teardown only if non-zero mcr is specified.