Configurable gigabits switch adapter
First Claim
1. In a data transmission system, a method for transforming fixed length cells, each cell having a payload, into user frames, each of said fixed length cells being preceded by a fixed size header, the payload and said fixed size header of each of said fixed length cells being processed separately, said method comprising the following steps:
- receiving said fixed length cells,feeding said fixed length cells in parallel into a parallel bus (54),separating said payload of the fixed length cell from said fixed size header, said payload being transmitted along said parallel bus (54) via a realignment unit (47) to a buffer memory (52),processing said fixed size header separately to determine a storage address of a storage section in said buffer memory (52),shifting said payload to the boundary of said parallel bus by means of said re-alignment unit (47),buffering said payload in said storage section in said buffer memory (52) made accessible by said storage address after being shifted to the bus boundary,supporting at least one virtual channel by employing a control section corresponding to said virtual channel, said control section comprising queuing means whereby the storage addresses of the storage sections in said buffer memory (52) which have been allocated by said virtual channel are stored, the buffered payload of said virtual channel being accessible by reading said storage addresses from said buffer memory (52).
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Accused Products
Abstract
The present invention relates to a data transmission system and concerns a method for transforming user frames into fixed length cells, e.g. ATM (Asynchronous Transfer Mode), such that the fixed length cells can be transported through a cell handling switch fabric (11). A hardware implementation of this method consists of two parts, a transmitter (12.1) and a receiver (13.1), both being part of a switching subsystem (10) comprising a switch fabric (11). The transmitter (12.1) buffers user data and segments them into fixed length cells to be transported through said switch (11). The receiver part (13.1) reassembles user data on reception of these cells.
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Citations
17 Claims
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1. In a data transmission system, a method for transforming fixed length cells, each cell having a payload, into user frames, each of said fixed length cells being preceded by a fixed size header, the payload and said fixed size header of each of said fixed length cells being processed separately, said method comprising the following steps:
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receiving said fixed length cells, feeding said fixed length cells in parallel into a parallel bus (54), separating said payload of the fixed length cell from said fixed size header, said payload being transmitted along said parallel bus (54) via a realignment unit (47) to a buffer memory (52), processing said fixed size header separately to determine a storage address of a storage section in said buffer memory (52), shifting said payload to the boundary of said parallel bus by means of said re-alignment unit (47), buffering said payload in said storage section in said buffer memory (52) made accessible by said storage address after being shifted to the bus boundary, supporting at least one virtual channel by employing a control section corresponding to said virtual channel, said control section comprising queuing means whereby the storage addresses of the storage sections in said buffer memory (52) which have been allocated by said virtual channel are stored, the buffered payload of said virtual channel being accessible by reading said storage addresses from said buffer memory (52). - View Dependent Claims (2, 3, 4, 5)
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6. In a data transmission system, a method for transforming a user frame into a fixed length cell, said fixed length cell being preceded by a fixed size header, the method comprising the steps of:
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buffering the payload of said user frame in a storage section of a buffer memory (24'"'"') using a storage address of said storage section, keeping said storage address in a queue (28.1'"'"', 28.2'"'"') such that said payload can be retrieved from said buffer memory (24'"'"') by taking said storage address from said queue (28.1'"'"', 28.2'"'"'), generating and processing said fixed size header separately prior to prefixing said payload with said fixed size header, taking said payload out of said buffer memory (24'"'"') using said corresponding storage address and inserting said payload into a fixed length cell, and transmitting said fixed length cell consisting of said payload preceded by said fixed size header. - View Dependent Claims (7, 8, 9, 10)
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11. Apparatus for transforming fixed length cells into user frames, each of said fixed length cells being preceded by a fixed size header, comprising:
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means for receiving a fixed length cell and transmitting said fixed length cell in parallel via a parallel bus, means (23) for separating the payload of said fixed length cell from said fixed size header transmitted via said parallel bus, header processor (22), connected to said parallel bus, for separately processing said fixed size header, to determine a storage address of a storage section in a buffer memory (24), re-alignment means for shifting said payload, received via said parallel bus, to the boundary of said parallel bus, means (23.3, 23.4) for buffering said payload, after said payload has been separated from said fixed size header and has been realigned, until said storage address is available, means (24,
26) for storing said payload in a storage section of said buffer memory (24) made accessible by said storage address,queuing means (25) for keeping said storage address corresponding to said payload in a queue, means for retrieving said payload from said storage section by successively taking the respective storage addresses from the queue of said queuing means (25), means for forming said user frame with said retrieved payload, in accordance with a predetermined data transmission protocol, and means for the transmission of said user frames. - View Dependent Claims (12, 13)
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14. Apparatus for transforming user frames, each comprising a payload into fixed length cells, each of said fixed length cells being preceded by a fixed size header, the apparatus comprising:
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means for buffering the payloads of said user frames in a storage section of a buffer memory (24'"'"'), queuing means (28.1'"'"', 28.2'"'"') for keeping the storage address of said storage section in a queue being part of said queuing means, header processor (22'"'"') taking said storage address from the queue of said queuing means (28.1'"'"', 28.2'"'"') and generating a fixed size header, means for retrieving said payload from said buffer memory (24'"'"') using said storage address taken from said queue, means for forming said fixed length cell by prefixing a part of said retrieved payload with said header, and means for transmitting said fixed length cell. - View Dependent Claims (15, 16, 17)
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Specification