Patent ID: 8107362

Claim:
An add/drop device for connecting at least two network dual rings to a single link layer interface, said device comprising: a first and a second port for each of said at least two network dual rings for receiving signals from or transmitting signals to each of said at least two network dual rings; first and second multiplexing framer means adapted for: combining at least two data signals having their own input data rates into a single output data streams having an output data rates higher than said input data rates of said data signals; splitting a single input data stream having an input data rate into at least two data signals having their own output data rates, lower than said input data rate of said single input data stream; said first multiplexing framer means receiving signals from or transmitting signals to said first ports and said second multiplexing framer means receiving signals from or transmitting signals to said second ports; add/drop means adapted for: extracting data from a single output data stream received from one of said first and second multiplexing framer means and transmitting said extracted data to said link layer interface; inserting data received from said link layer interface to a single output data stream received from one of said first and second multiplexing framer means; transmitting a single output data stream received from one of said first and second multiplexing framer means, wherein data may have been extracted or inserted, to one of said first and second multiplexing framer means, wherein said add/drop means consists of a single device interfacing each of said first and second multiplexing framer means and said link layer and comprises: first frame header parsing means associated to said first multiplexing framer means and second frame header parsing means associated to said second multiplexing framer means; first frame decapsulation means associated to said first multiplexing framer means and second frame decapsulation means associated to said first multiplexing framer means; memorization means; wherein frames received from one of said first and second multiplexing framer means are parsed in associated frame header parsing means and packets that have to be transmitted to said link layer interface are decapsulated out of the frames in associated frame decapsulation means and stored in said memorization means.