With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
rprSpanStatsInUcastClassBCirFrames
rpr Span Stats In Ucast Class B Cir Frames
1.0.8802.17.1.1.1.3.4.1.5
The number of received (PHY to MAC) classB CIR unicast frames.
Back to IEEE-802DOT17-RPR-MIB MIB page.
IPHost Network monitor allows you to monitor rprSpanStatsInUcastClassBCirFrames on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco switches right now.