| 摘要 |
PROBLEM TO BE SOLVED: To reduce an incidence rate of system down, etc., by performing multimedia stream communication while suppressing the construction cost of the whole system and activating a communication system for backup even when a single communication system is broken. SOLUTION: An operation system gateway device 9 having a function for mutually converting a protocol for multimedia data stream communication and that for general inter-LAN communication, a standby system gateway device 10 and a line switching device 6 for selecting one of these operation system gateway device 9 and standby system gateway device 10 and connecting it to an ISDN line 5. Respective LANs 3a and 3b provided at an information center 2 are connected to the ISDN line 5 connected to a portable traffic network 8 through these operation system gateway device 9 and standby system gateway device 10 and the line switching device 6. |
