With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
mplsInterfacePerfInLabelsInUse
mpls Interface Perf In Labels In Use
1.3.6.1.3.96.1.2.1.1
This object counts the number of labels that are in use at this point in time on this interface in the incoming direction. If the interface participates in only the per-platform label space, then the value of the instance of this object MUST be identical to the value of the instance with index 0. If the interface participates in the per-interface label space, then the instance of this object MUST represent the number of per-interface labels that are in use on this interface.
Back to MPLS-LSR-STD-MIB MIB page.
IPHost Network monitor allows you to monitor mplsInterfacePerfInLabelsInUse on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco mobile switches right now.