With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cgrtDestMSUsOut
Cisco IP Transfer Point GRT Dest MS Us Out
1.3.6.1.4.1.9.9.334.1.2.2.1.6
The number of MSUs that were queued to linkset for transmission to this destination. Management MSUs that originate from this signalling point are also counted. It is important to note that, in rare cases, MSU discards due to any abnormal system resource error conditions may be included in this count.
Back to CISCO-ITP-GRT-MIB MIB page.
IPHost Network monitor allows you to monitor cgrtDestMSUsOut on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.