With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cgspLinkL2BytesSent
Cisco GSP Link L2 Bytes Sent
1.3.6.1.4.1.9.9.336.1.6.1.1.87
A count of the bytes sent on the link including the additional bytes required by underlying protocols. This provides a transport independent mechanism for collection information on link utilization.
Back to CISCO-ITP-GSP-MIB MIB page.
IPHost Network monitor allows you to monitor cgspLinkL2BytesSent on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.