Error Detection And Management - Sun Microsystems storagetek sl500 Reference Manual

Error Detection and Management

In the Fibre Channel protocol, error detection falls into two categories: frame errors
and link-level errors.
Frame errors result in missing or corrupted frames, which may ultimately
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involve the Fibre Channel protocol level to resolve.
Link-level errors include errors such as loss of signal, loss of synchronization,
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and timeouts.
Some protocols provide for error detection and management by using timeouts,
which is an inefficient mechanism to detect and recover from frame transmission
errors.
A problem with Class 3 operation (currently the only FC-2 Service Class
supported) is that it offers no confirmation of frame delivery. However, the
originator can deduce some delivery of frames from successfully receiving a
command when:
FCP Transfer Ready was sent by the command recipient
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A response was received
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Fibre Channel provides no error correction on data during transfers, but it does
provide excellent error detection schemes, including:
8B/10B encoding and decoding (see
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page
Disparity (see
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Sequence errors and out-of-order delivery (see
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Cyclic redundancy checks (CRC) (see
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96122 • Revision: F
45)
"Disparity" on page
Error Detection and Management
"8B/10B Encoding and Decoding" on
45)
"Sequence Errors" on page
"CRC" on page 64)
Chapter 5 Fibre Channel Operations 43
64)