Patent ID: 7492719

Claim:
A method of controlling a loop-back process between a local device and a remote device in an Ethernet passive optical network, the method comprising the steps of: (a) providing a predetermined field in a loop-back control OAM PDU (operation, administration, and maintenance—packet data unit), the predetermined field having distinguishing messages for an initiation of the loop-back process and a termination of the loop-back process; and (b) the local device and the remote device performing the loop-back process, which includes an initiation of the loop-back process and a termination of the loop-back process, using the loop-back control OAM PDU, wherein the loopback process performed by using the loop-back control OAM PDU into which the distinguishing messages of the predetermined field are added, further comprises: a loopback process initiation step of transmitting, by the local device, a loop-back control OAM PDU requesting the initiation of the loop-back process to the remote device; and a loopback process termination step of transmitting, by the local device, a loop-back control OAM PDU requesting the termination of the loopback process to the remote device, wherein the predetermined field includes one of: a first field value representing a message requesting an initiation of a loop-back process; a second field value representing a message acknowledging the initiation request message of the loop-back process; a third field value representing a message requesting a termination of the loop-back process from the local device to the remote device; a fourth field value representing a message requesting a termination of the loop-back process from the remote device to the local device; and a fifth field value representing a message acknowledging the fourth field value from the local device to the remote device.