With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
ccmPhoneName
Cisco Call Manager Phone Name
1.3.6.1.4.1.9.9.156.1.2.1.1.20
The name of the phone. The name of the phone can be + MAC Address, where is SEP for Cisco SCCP and SIP Phones. In the case of other phones such as communicator (soft phone) it can be free-form name, a string which uniquely identifies the phone.
Back to CISCO-CCM-MIB MIB page.
IPHost Network monitor allows you to monitor ccmPhoneName on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco multiplexers right now.