Brocade Communications Systems Network Advisor 12.3.0, Руководство пользователя

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1224 Brocade Network Advisor SAN User Manual
53-1003154-01
Frame Monitor
30
Pre-defined frame types
Pre-defined frame types include the following:
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ABTS (Abort Sequence Basic Link Service command)
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BA_ACC (Abort Accept)
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IP
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SCSI
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SCSI Read
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SCSI Write
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SCSI RW
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SCSI-2 Reserve
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SCSI-3 Reserve
Custom frame types
In addition to the standard frame types, you can create custom frame types to gather statistics that
fit your needs. To define a custom frame type, you must specify a series of
offsets , bitmasks , and
values . For all transmitted frames, the switch performs these tasks:
•
Locates the byte found in the frame at the specified offset.
•
Applies the bitmask to the byte found in the frame.
•
Compares the new value with the given value .
•
Increments the filter counter if a match is found.
You can specify up to four values to compare against each offset. If more than one offset is
required to properly define a filter, the bytes found at each offset must match one of the given
values for the filter to increment its counter. If one or more of the given offsets does not match any
of the given values, the counter does not increment. The value of the offset must be between 0 and
63, in decimal format. Byte 0 indicates the first byte of the Start of Frame (SOF), byte 4 is the first
byte of the frame header, and byte 28 is the first byte of the payload. Thus only the SOF, frame
header, and first 36 bytes of payload can be selected as part of a filter definition. Offset 0 is a
special case, which can be used to monitor the first 4 bytes of the frame (SOF). When the offset is
set to 0, the values 0–7 that are checked against that offset are predefined as shown in
Table 104 .
TABLE 104 Predefined values at offset 0
Value SOF Value SOF
0 SOFf 4 SOFi2
1 SOFc1 5 SOFn2
2 SOFi1 6 SOFi3
3 SOFn1 7 SOFn3