| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reliably deliver conference data to computers participating in a hierarchically arranged multi-cast conference session. <P>SOLUTION: When a slave computer does not receive a multi-cast packet (an IP multi-cast packet, for example), the slave computer transmits a negative acknowledgement to a master computer. In response, the master computer re-transmits the conference data which are contained in the multi-cast packet to the slave computer. Conference data can be re-transmitted to the slave computer via uni-cast (TCP, for example). Therefore, the conference data which are not received or are damaged via multi-cast can be repaired via uni-cast. Computers can join an existing multi-cast conference session without having to communicate with a root computer. The root computer adjusts a multi-cast send rate to compensate for changed network conditions. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
