With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cpmActiveRemotePhoneNumber
cpm Active Remote Phone Number
1.3.6.1.4.1.9.10.19.1.3.1.1.12
The remote telephone number. For a call into the device, this is the originating number. For a call out of the device, this is the dialed number. If not available the string length is zero.
Back to CISCO-POP-MGMT-MIB MIB page.
IPHost Network monitor allows you to monitor cpmActiveRemotePhoneNumber on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco wireless switches right now.
