Patent ID: 7593997
Filing Date: 2009-09-22
Classification: G06F,H04L

Abstract:
1. A Fibre Channel switch element in a Fibre Channel network, comprising: a port having (i) a receive segment for receiving a fibre channel frame; (ii) a transmit segment for transmitting a fibre channel frame; (iii) a control segment that stores an indicator value to identify whether an entire logical unit number (LUN) field in a FCP_CMND frame is to be replaced; or an offset value is to be added or subtracted from the FCP_CMD frame; and (iv) a hardware based LUN mapping cache that replaces the entire LUN field value in the FCP_CMND frame with the new LUN field value; or adds the offset value to the FCP_CMND frame or subtracts the offset value from the FCP_CMND frame based on the indicator value, wherein for each replaced LUN field value in the FCP CMND frame; a cyclic redundancy code (CRC) field value is replaced by a newly computed CRC value using the new LUN field value, and wherein the LUN Mapping cache generates the offset value that is either added to or subtracted from the LUN field value in the FCP CMND frame based on the indicator value.