| Router>enable | Enables privileged EXEC mode. Enter your password if prompted. |
| Router# configure terminal | Enters global configuration mode. |
| Router(config)# voice service voip | Enters voice service configuration mode and specifies Voice over IP (VoIP) encapsulation. |
| Router(config-voi-srv)# allow-connections h323 to h323 | Enables calls between specific types of endpoints in a VoIP network. |
| Router(config-voi-srv)# allow-connections h323 to SIP | Enables calls between specific types of endpoints in a VoIP network. |
| Router(config-voi-srv)# allow-connections SIP to SIP | Enables calls between specific types of endpoints in a VoIP network. |
| | NOTE: A separate allow-connections command is required for each type of endpoint to be supported. |
| Router(config-voi-srv)# sip | Enters SIP configuration mode. |
| | NOTE: Required if you are connecting IP phones running SIP directly in Cisco CME 3.4 and later. |
| Router(config-voi-sip)# registrar server expires max 600 min 60 | Enables SIP registrar functionality in Cisco Unified CME with lowest values. |
| | NOTE: Cisco Unified CME does not maintain a persistent database of registration entries across CME router reloads. SIP phones will have to register again. |
| | NOTE: Cisco recommends setting the timers to their minimum values. |