With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cGgsnExtHistCreatedPDPs
cisco Gateway GPRS Support Node Ext History Created PD Ps
1.3.6.1.4.1.9.9.647.1.1.16.1.4
This object indicates the historical number of PDP contexts created in a specific sampling period specified by cGgsnExtCallRateInterval.
Back to CISCO-GGSN-EXT-MIB MIB page.
IPHost Network monitor allows you to monitor cGgsnExtHistCreatedPDPs 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.