Fujitsu MBA3147RC Manuel D’Utilisation
1.1 Topologies in SAS Interface
C141-C013
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1.1.5 Pathways
A potential pathway is a set of physical links between a SAS INIT phy and a SAS
TARG phy. When a SAS INIT phy is directly attached to a SAS TARG phy,
there is one potential pathway. When there are expander devices between a SAS
INIT phy and a SAS TARG phy, there are multiple potential pathways, each
consisting of a set of physical links between the SAS INIT phy and the SAS
TARG phy. The physical links may or may not be using the same physical link
rate.
TARG phy. When a SAS INIT phy is directly attached to a SAS TARG phy,
there is one potential pathway. When there are expander devices between a SAS
INIT phy and a SAS TARG phy, there are multiple potential pathways, each
consisting of a set of physical links between the SAS INIT phy and the SAS
TARG phy. The physical links may or may not be using the same physical link
rate.
A pathway is a set of physical links between a SAS INIT phy and a SAS TARG
phy being used by a connection.
phy being used by a connection.
Figure 1.6 shows examples of potential pathways.
Figure 1.6 Example of potential pathways
A partial pathway is the set of physical links participating in a connection request
that has not reached the destination phy (e.g., the OPEN address frame has been
transmitted by the source phy but the OPEN address frame has not yet reached the
destination phy).
that has not reached the destination phy (e.g., the OPEN address frame has been
transmitted by the source phy but the OPEN address frame has not yet reached the
destination phy).
A partial pathway is blocked when path resources it requires are held by another
partial pathway.
partial pathway.