| 摘要 |
<p>PURPOSE:To efficiently process a fault and system reopening so as to provide users with highly stable packet switching service by connecting maintenance information and subscriber's line state information to a packet switchboard in a time division multiplexed form. CONSTITUTION:Interface devices (U-INF) 1 and 2 respectively house digital subscriber's lines 3 and 4 of a (2B+D) basic access system and monitor states of layers 1 of the lines 3 and 4. The U-INFs 1 and 2 respectively separate B (B1 and B2) channels and D channels from each other and send the packets using the B channels to a packet switchboard 6 through a switch matrix 5 and the packets using the D channels to LAPD handlers 7 and 8. The U-INFs 1 and 2 also respectively send packets from the device 6 or handlers 7 and 8 to the subscriber's lines 3 and 4 and the packets form the handlers 7 and 8 monitor the termination and state of the layers 2 of the subscriber's lines 3 and 4.</p> |
