McDATA ULTRANETTM EDGE STORAGE ROUTER 3000 - Manual (Page 66)

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3-12 McDATA UltraNet Edge 3000 User Guide
Fibre Channel Frame Level CRC
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 Card The FCBB Fibre Channel PCI adapter card transmits and receives the
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
the FCXL2 Card When powering up or resetting the UltraNet Edge 3000, the FCXL2
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.
Table 3-3 Non-Supported Applications for E_Port Disk Streaming
Non-Supported
Storage Device Applications/Protocols
IBM Shark (ESS) • PPRC-XD
Smartbits • Frame Blaster