<s>
The	O
arbitrated	B-Architecture
loop	I-Architecture
,	O
also	O
known	O
as	O
FC-AL	B-Architecture
,	O
is	O
a	O
Fibre	B-Architecture
Channel	I-Architecture
topology	O
in	O
which	O
devices	O
are	O
connected	O
in	O
a	O
one-way	O
loop	O
fashion	O
in	O
a	O
ring	B-Architecture
topology	I-Architecture
.	O
</s>
<s>
Historically	O
it	O
was	O
a	O
lower-cost	O
alternative	O
to	O
a	O
fabric	B-Architecture
topology	I-Architecture
.	O
</s>
<s>
It	O
allowed	O
connection	O
of	O
many	O
servers	B-Application
and	O
computer	B-General_Concept
storage	I-General_Concept
devices	I-General_Concept
without	O
using	O
then	O
very	O
costly	O
Fibre	B-Architecture
Channel	I-Architecture
switches	I-Architecture
.	O
</s>
<s>
The	O
cost	O
of	O
the	O
switches	O
dropped	O
considerably	O
,	O
so	O
by	O
2007	O
,	O
FC-AL	B-Architecture
had	O
become	O
rare	O
in	O
server-to-storage	O
communication	O
.	O
</s>
<s>
It	O
is	O
however	O
still	O
common	O
within	O
storage	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
It	O
is	O
a	O
serial	B-Protocol
architecture	O
that	O
can	O
be	O
used	O
as	O
the	O
transport	O
layer	O
in	O
a	O
SCSI	B-Architecture
network	O
,	O
with	O
up	O
to	O
127	O
devices	O
.	O
</s>
<s>
The	O
loop	O
may	O
connect	O
into	O
a	O
fibre	B-Architecture
channel	I-Architecture
fabric	I-Architecture
via	O
one	O
of	O
its	O
ports	O
.	O
</s>
<s>
Fibre	B-Architecture
Channel	I-Architecture
ports	O
capable	O
of	O
arbitrated	B-Architecture
loop	I-Architecture
communication	O
are	O
NL_port	O
(	O
node	O
loop	O
port	O
)	O
and	O
FL_port	O
(	O
fabric	O
loop	O
port	O
)	O
,	O
collectively	O
referred	O
to	O
as	O
the	O
L_ports	O
.	O
</s>
<s>
An	O
arbitrated	B-Architecture
loop	I-Architecture
with	O
no	O
fabric	O
port	O
(	O
with	O
only	O
NL_ports	O
)	O
is	O
a	O
private	O
loop	O
.	O
</s>
<s>
An	O
arbitrated	B-Architecture
loop	I-Architecture
connected	O
to	O
a	O
fabric	O
(	O
through	O
an	O
FL_port	O
)	O
is	O
a	O
public	O
loop	O
.	O
</s>
<s>
Arbitrated	B-Architecture
loop	I-Architecture
can	O
be	O
physically	O
cabled	O
in	O
a	O
ring	O
fashion	O
or	O
using	O
a	O
hub	O
.	O
</s>
