Connect Cisco Voice Gateway to use a SIP Proxy Server

Cisco Voice Gateway Configuration:

Router#conf t
Router(config)#sip-ua
Router(config-sip-ua)#sip-server ipv4:10.1.1.1
Router(config-sip-ua)#exit

Router#conf t
Router(config)#dial-peer voice 15 voip
Router(config-dial-peer)#destination-pattern ....
Router(config-dial-peer)#session protocol sipv2
Router(config-dial-peer)#session target sip-server
Router(config-dial-peer)#exit

Router#conf t
Router(config)#dial-peer voice 16 voip
Router(config-dial-peer)#destination-pattern ....
Router(config-dial-peer)#session protocol sipv2
Router(config-dial-peer)#session target ipv4:5.5.5.5
Router(config-dial-peer)#exit

Explanation:

*sip-ua (sip user agent, initiate request to a SIP voice proxy server)
*10.1.1.1 Ip address SIP Cisco Proxy server
*Use dial plan 15 if you need to send any 4 digit extension request to CISCO SIP proxy server
*Use dial plan 16 if you need to send any 4 digit extension request to other 3rd party SIP proxy server