| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an ONU in which the communication band in PON section can be utilized effectively by suppressing useless transmission of multicast control message to the PON section. <P>SOLUTION: An ONU of a PON system includes a multicast group management table 260 indicating the correspondence between a multicast group identifier and the address of a user terminal participating in multicast group, and registers the correspondence between the multicast group identifier and the address of the user terminal indicated by a received message when a message for requesting participation to a multicast group is received from the user terminal. If the address of the other user terminal has already been registered on the multicast group management table in association with the same multicast group identifier, the received new message is not transferred to the OLT but discarded. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
