With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cSipStatsSuccessOkInbounds
Cisco Sip Stats Success Ok Inbounds
1.3.6.1.4.1.9.9.152.1.2.2.5.1.2
This object reflects the total number of Ok (200) responses sent by the user agent, since system startup, that were associated with the SIP method as specified by cSipStatsSuccessOkMethod.
Back to CISCO-SIP-UA-MIB MIB page.
IPHost Network monitor allows you to monitor cSipStatsSuccessOkInbounds 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.