With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
voicePortIfGatewayAddress
voice Port If Gateway Address
1.3.6.1.4.1.9.5.1.26.1.1.7
is configurable only if voicePortIfDHCPEnabled is false.
Back to CISCO-STACK-MIB MIB page.
IPHost Network monitor allows you to monitor voicePortIfGatewayAddress on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.