A method of transmitting a message from a security system to a central station receiver includes receiving at the security system an IP address associated with the central station receiver. An attempt is made to transmit the message from the security system to the central station receiver by use of the IP address. In response to a failure to receive at the security system an acknowledgement from the central station receiver that the message was received, the security system is used to query a Domain Name Server for a current IP address associated with the central station receiver. The query is dependent upon a domain name of the central station receiver. The current IP address associated with the central station receiver is received and used to re-attempt the transmitting of the message from the security system to the central station receiver.