A method for registering an IP phone linked to a first telephony server and a second telephony server in a dual-link architecture, comprising: pre-registering the IP phone to establish client links with the first telephony server and the second telephony server, comprising: the IP phone identifying the first telephony server and the second telephony server designated for the IP phone in the dual-link architecture; and sending registration requests to the first telephony server and the second telephony server from the IP phone to pre-register the IP phone with each of the first telephony server and second telephony server; setting one of the first telephony server or second telephony server as a primary telephony server , comprising sending an in-service request from the IP phone to one of the first telephony server and second telephony server to identify the primary telephony server for the IP phone and setting the remaining server of the first telephony server and second telephony server as a secondary server in a hot standby mode with the IP phone; and conducting a fail-over process for the IP phone from the primary telephony server to the secondary telephony server, comprising: sending an out-service request from the IP phone to the primary telephony server, the out-service request being configured to place the primary telephony server into a hot-standby mode with the IP phone; sending an in-service request from the IP phone to one of the first telephony server and second telephony server that is not the primary telephony server to act as the secondary telephony server; and receiving an in-service acknowledgment from the secondary telephony server at the IP phone. the IP phone identifying the first telephony server and the second telephony server designated for the IP phone in the dual-link architecture; and sending registration requests to the first telephony server and the second telephony server from the IP phone to pre-register the IP phone with each of the first telephony server and second telephony server; setting one of the first telephony server or second telephony server as a primary telephony server , comprising sending an in-service request from the IP phone to one of the first telephony server and second telephony server to identify the primary telephony server for the IP phone and setting the remaining server of the first telephony server and second telephony server as a secondary server in a hot standby mode with the IP phone; and conducting a fail-over process for the IP phone from the primary telephony server to the secondary telephony server, comprising: sending an out-service request from the IP phone to the primary telephony server, the out-service request being configured to place the primary telephony server into a hot-standby mode with the IP phone; sending an in-service request from the IP phone to one of the first telephony server and second telephony server that is not the primary telephony server to act as the secondary telephony server; and receiving an in-service acknowledgment from the secondary telephony server at the IP phone. sending an in-service request from the IP phone to one of the first telephony server and second telephony server that is not the primary telephony server to act as the secondary telephony server; and receiving an in-service acknowledgment from the secondary telephony server at the IP phone. <EOS>