Redundant structure control device for exchange

A redundant structure control device for an exchange having a spare line, comprising

• frame tag attaching means for attaching a routing header to a frame coming in from lines or line interface devices and giving tag information in said routing header,
• frame switching means for switching a destination of said frame to which tag information has been given, in accordance with said tag information,
• line trouble monitoring means arranged between said lines and said frame switching means, for monitoring line trouble, and
• routing control means for identifying, based on line trouble information from said line trouble monitoring means, a line interface device connected with a line at which trouble has happened, and arranging said frame tag attaching means so that a frame coming from said identified line interface device towards said line at which trouble has happened may be sent out to said spare line.

A redundant structure control device for an exchange having a set of a spare line and a spare line interface device, comprising

• frame tag attaching means for attaching a routing header to a frame coming in from lines or line interface devices and giving tag information in said routing header,
• frame switching means for switching a destination of said frame to which tag information has been given, in accordance with said tag information,
• line trouble monitoring means arranged between said lines and said frame switching means, for monitoring line trouble,
• routing control means for monitoring states of said line interface devices, and when trouble happens at one of said line interface devices, sending out a control signal to said frame tag attaching means so that a frame coming from a line originally connected with said line interface device at which trouble has happened may be switched over to said spare line interface device, and arranging said frame tag attaching means so that a frame coming from said spare line interface device may flow to said line originally connected with said line interface device at which trouble has happened;
• and identifying, based on line trouble information from said line trouble monitoring means, a line interface device connected with a line at which trouble has happened, and arranging said frame tag attaching means so that a frame coming from said identified line interface device towards said line at which trouble has happened may be sent out to said spare line, and
• tag changing means provided in an asynchronous transmission mode concentrator arranged between said line interface devices and an asynchronous transmission mode switch, for changing a value of a tag of a cell indicating that the cell should be sent from said asynchronous transmission mode switch to a line interface device at which trouble has happened, to a value indicating that the cell should be routed to said spare line interface device, in accordance with instructions provided by said routing means when said routing means detects trouble happening at one of said line interface devices.