With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cmiMnRegistrationTable
Cisco Mobile IP Mn Registration Table
1.3.6.1.4.1.9.9.174.1.5.2.1
A table containing information about the mobile node's attempted registration(s). The mobile node updates this table based upon Registration Requests sent and Registration Replies received in response to these requests. Certain variables within this table are also updated when Registration Requests are retransmitted.
Back to CISCO-MOBILE-IP-MIB MIB page.
IPHost Network monitor allows you to monitor cmiMnRegistrationTable 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.