Abstract: A method and apparatus is presented for performing a sequence-level CRC calculation on fiber channel communications within a switching platform domain. A CRC generator searches the data communication for frames that contain the type of data for which a sequence-level CRC is desired, such as for a sequence containing SCSI data. If found, and the type of data allows multiple frames per sequence, the present invention creates a CRC value for the sequence. An intermediate CRC value is stored in a queue to allow the simultaneous calculation of sequence level CRC values for multiple frames. With inbound data, the sequence-level CRC is appended to the end of the sequence data. With outbound data, the calculated value is compared with the appended, expected value, With single-frame fiber channel protocols, the frame-level CRC value is obtained directly from the frames entering the switching platform domain.

Abstract: A method and apparatus is presented for performing a sequence-level CRC calculation on fibre channel communications within a switching platform domain. A CRC generator searches the data communication for frames that contain the type of data for which a sequence-level CRC is desired, such as for a sequence containing SCSI data. If found, and the type of data allows multiple frames per sequence, the present invention creates a CRC value for the sequence. An intermediate CRC value is stored in a queue to allow the simultaneous calculation of sequence level CRC values for multiple frames. With inbound data, the sequence-level CRC is appended to the end of the sequence data. With outbound data, the calculated value is compared with the appended, expected value, With single-frame fibre channel protocols, the frame-level CRC value is obtained directly from the frames entering the switching platform domain.

Abstract: A method and apparatus is presented for performing a sequence-level CRC calculation on fiber channel communications within a switching platform domain. Specifically, the disclosed invention utilizes a CRC generator to monitor data communication between an external interface and a fiber channel controller. The CRC generator searches the data communication for frames that contain the type of data for which a sequence-level CRC is desired, such as for a sequence containing SCSI data. When found, the CRC generator performs an 8B/10B decode, strips off any fill bytes, and performs a CRC calculation on the data payload. If the found frame is the first frame in the sequence, the CRC is done starting with a reset value. If the frame is not the first, an intermediate value containing the previous CRC calculation results for this sequence is retrieved and used to perform the CRC calculations. Upon completion of the calculation for the frame, a determination is made whether the sequence is complete.

Abstract: A method and apparatus is presented providing high-performance lossless data compression implemented in hardware for improving network communications. A compression module useful in a switching platform is also presented capable of compressing data stored in buffer memory. Instructions for a compression task are assigned to the compression module by a microprocessor writing a control block to a queue in stored local memory. The control block informs the compression module of the size and location of the unprocessed data, as well as a location in the buffer memory for storing the processed data and the maximum allowed size for the compressed data. Using this technique, the microprocessor can limit the compression of data to those data streams allowing compression, to those segments that are susceptible to compression, and to those segments that are large enough to show a transmission speed improvement via compression.