With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cgrtDestSIOctetsOut
Cisco IP Transfer Point GRT Dest SI Octets Out
1.3.6.1.4.1.9.9.334.1.2.6.1.3
The number of outgoing octets that were queued to linkset for transmission to this specific destination and service indicator. It is important to note that, in rare cases, octets discarded 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 cgrtDestSIOctetsOut 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.