With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ccmPhoneExtnStatus
Cisco Call Manager Phone Extension Status
1.3.6.1.4.1.9.9.156.1.2.5.1.6
Represents the status of this phone line.
Back to CISCO-CCM-MIB MIB page.
IPHost Network monitor allows you to monitor ccmPhoneExtnStatus on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco optical switches right now.