With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
c3gSipUsername
Cisco 3G Sip Username
1.3.6.1.4.1.9.9.661.1.2.4.1.8
Simple IP (SIP) user name.
Back to CISCO-WAN-3G-MIB MIB page.
IPHost Network monitor allows you to monitor c3gSipUsername on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco routers right now.