| 摘要 |
With respect to first to 11th DSL subscriber line termination units ( 112 - 1 to 112 - 11 ) each terminating subscriber lines for a plurality of channels on a board, there is provided an auxiliary DSL subscriber line termination unit ( 112 - 12 ) terminating the same number of subscriber lines on a board. Upon occurrence of failure corresponding to any of the channels, a redundant control panel ( 114 ) implements switching to a corresponding channel of the auxiliary DSL subscriber line termination unit. By this switching, a physical interface number of a packet is changed. However, it can be dealt with by conversion to the same logical interface number as before using a mapping table ( 212 ) under the control of a protection control section ( 215 ). |
