With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
fcmPortClass2RxFbsyFrames
fcm Port Class2 Rx Fbsy Frames
1.3.6.1.2.1.10.56.1.4.1.8
The number of times that F_BSY was returned to this port as a result of a Class 2 frame that could not be delivered to the other end of the link. This can occur when either the fabric or the destination port is temporarily busy. Note that this counter will never increment for an F_Port.
Back to FC-MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor fcmPortClass2RxFbsyFrames 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.