| 摘要 |
<p>A control signal processor which reduces overhead in switching physical signal links. A physical signal link (layer-1 link) is switched while holding a layer-2 link in an OSI reference model. Specifically, the control signal processor has a data base (11) which stores a plurality of physical signal links and corresponding maximum lengths of a layer-2 frame determined by the capability of each physical signal link and which, when switching the physical signal link currently used by a single layer-2 link, selects a destination physical signal link, switches the physical signal link currently used by the single layer-2 link to the destination physical signal link without releasing the single layer-2 link, retrieves from the data base (11) the maximum length corresponding to the destination physical signal link, and sends the layer-2 frame of the maximum length. The switching of the physical signal link is performed as follows. First, when a physical signal link switch request is given, the control signal processor requests the setting of the destination physical signal link without releasing the layer-2 link to start multiple reception of a control signal using both the destination physical signal link and the originating physical signal link. After checking that the destination physical signal link has been established, the processor switches the physical signal link to be used for the transmission of the control signal to the destination physical signal link and requests the release of the originating physical signal link. After confirming the release of the originating physical signal link, the processor switches the physical signal link used for receiving the control signal to only the destination physical signal link.</p> |
