McDATA 3000 Fibre Channel Frame Level CRC, Non-Supported Storage Device Applications/Protocols

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Fibre Channel Frame Level CRC

Table 3-3Non-Supported Applications for E_Port Disk Streaming

Non-Supported
Storage Device	Applications/Protocols
IBM Shark (ESS)	•	PPRC-XD
Smartbits	•	Frame Blaster

Fibre Channel Frame Level CRC

This section provides information for Fibre Channel Frame Level

CRC (Cyclic Redundancy Check).

Frame Level CRC (Cyclic Redundancy Check) support is automatically enabled for FCIP (Fibre Channel over IP) configurations when either the FCBB or FCXL2 Fibre Channel card is installed.

When a Fibre Channel frame is received, hardware on the Fiber Channel PCI adapter card validates the data with the embedded CRC field. If the CRC check is valid for the CRC value received for this frame, the Fibre Channel driver will store and forward this value to its peer Fibre Channel PCI adapter.

Frame Level CRC on The FCBB Fibre Channel PCI adapter card transmits and receives the

the FCBB Card Fibre Channel frame in its specified format. Upon a transmit, during the frame gathering transfer of buffer memory, is when a frame level CRC is performed. If the value contained in the frame is correct, it is transmitted. If not, then the frame is discarded and a log message is produced indicating a bad CRC on that frame.

Frame Level CRC on When powering up or resetting the UltraNet Edge 3000, the FCXL2

the FCXL2 Card Fibre Channel driver will determine if each attached Fibre Channel PCI card has hardware installed with CRC support. When the wide area connection is up, the FCXL2 Fibre Channel driver will exchange these capabilities with its peer. If both sides of the connection have CRC capabilities, frame level CRC is enabled. This exchange is done at each linkup event. The ON/OFF status of Frame level CRC is displayed in the FCXL2 dump backbone user interface command.

3-12 McDATA UltraNet Edge 3000 User Guide