With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cIdslItucPerfHdlcLongs
Cisco Idsl ITU-C Performance Hdlc Longs
1.3.6.1.4.1.9.9.154.1.6.1.8
This object specifies the number of long HDLC frames received by the ITU-C since agent reset. A long HDLC frame contains more than 1500 octets.
Back to CISCO-IDSL-LINE-MIB MIB page.
IPHost Network monitor allows you to monitor cIdslItucPerfHdlcLongs 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.