With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cvPeerCommonCfgTargetCarrierId
Cisco Voice Peer Common Configure Target Carrier Id
1.3.6.1.4.1.9.9.63.1.2.4.1.8
The object specifies the Target Carrier Id for the peer. The Target Carrier Id is used to match with the Target Carrier Id of a call. If the Target Carrier Id in this object is matched with the Target Carrier Id of a call, then the associated peer will be used to handle the call. Only alphanumeric characters, '-' and '_' are allowed in the string.
Back to CISCO-VOICE-DIAL-CONTROL-MIB MIB page.
IPHost Network monitor allows you to monitor cvPeerCommonCfgTargetCarrierId on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco mobile switches right now.