With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cCdmaSessionGREToIPPkts
Cisco Cdma Session GRE To IP Packets
1.3.6.1.4.1.9.9.157.1.3.1.1.27
Number of GRE encapsulated packets delivered to IP for transmission since system was last restarted.
Back to CISCO-CDMA-PDSN-MIB MIB page.
IPHost Network monitor allows you to monitor cCdmaSessionGREToIPPkts 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.