Digital cross connect and add/drop multiplexing device for SDH or SONET signals

The present invention concerns a multiplexing device for providing a digital cross connect and add/drop functionality to a SONET and/or SDH compliant signal intercon- nection device. The invention more particularly relates to a modular, non-blocking, expandable, digital interconnection system capable of cross-connecting lower-rate signals (tributaries), where these signals are components of higher rate signals, or may terminate on low speed lines (local ports). It even more specifically concerns a multi- plexing device for a SONET/SDH interconnection circuit employing like modules arranged in parallel, with the number of modules depending on the transmission speed of the SONET/SDH links served. In a communication network for transferring signals, e.g. according to the SONET or SDH standards, interconnecting node devices are provided consisting of parallel processing modules (-T, -R). A plurality of processing modules with first and second interfaces rearrange/insert/extract tributary signals and configurable multiplexing/de-multiplexing components enable each processing module to access any portion of an arbitrarily preselected tributary signal. In a SONET/SDH system, signals between SONET/SDH frames are rearranged on incoming () and outgoing () main lines=Digital Cross-Connect, or tributary signals are transferred between frames and local lines (-i-T, -i-R)=Add/Drop Function. The system provides configurable multiplexing/de-multiplexing components (-i, -i, -i, -i) which allow the processing modules to have access to any tributary signals in said frames, thus enabling digital cross-connect and add/drop operations without completely demultiplexing or disassembling frames. In a preferred embodiment, the configurable multiplexing/demultiplexing component includes a pipeline arrangement (-i, -i) connected to all processing modules (-T, -R).