Figure 1.4 Ports (Narrow Ports And Wide Ports) - Fujitsu MAU3147RC SERIES Technical Manual

A wide port is created if there is more than one phy in the port. A narrow port is a
port with only one phy.
A wide link is the set of physical links that attach a wide port to another wide
port. A narrow link is the physical link that attaches a narrow port to another
narrow port.
Figure 1.4 shows examples of narrow ports and wide ports, with a representation
of the SAS address transmitted during the identification sequence. Although
several phys on the left transmit SAS addresses of B, only phys attached to the
same SAS addresses become part of the same ports. The set of phys with SAS
address B attached to the set of phys with SAS address D become one port, while
the set of phys with SAS address B attached to the set of phys with SAS address E
become another port.
Narrow port
Phy
Wide port
Phy
Phy
Wide port
Phy
Phy

Figure 1.4 Ports (narrow ports and wide ports)

C141-C009
SAS address A
Narrow link
Physical link
SAS address C
SAS address B
Wide link
Physical link
SAS address D
SAS address B
SAS address D
Physical link
SAS address B
Wide link
Physical link
SAS address E
SAS address B
SAS address E
Physical link
1.1 Topologies in SAS Interface
Narrow port
Phy
Wide port
Phy
Phy
Wide port
Phy
Phy
1-5