| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve communication quality by eliminating a blank in performing switching from a VoIP server of an active system to a VoIP server for backup. <P>SOLUTION: A server device 10 unitarily manages client address information. A backup server device 20 backs up the server device 10. A client address information registering and notifying part 32 simultaneously registers the client address information in the active system server device 10 and the backup server device 20 and notifies the active system server device 10 and the backup server device 20 of the client address information. A communication control part 33 receives the IP address of an incoming call destination from the server device 10 or the backup server device 20 when communication with the server device 10 becomes impossible, and secures a set transmission band. <P>COPYRIGHT: (C)2003,JPO</p> |
