<s>
In	O
telephony	O
,	O
the	O
local	B-Architecture
loop	I-Architecture
(	O
also	O
referred	O
to	O
as	O
the	O
local	O
tail	O
,	O
subscriber	B-Architecture
line	I-Architecture
,	O
or	O
in	O
the	O
aggregate	O
as	O
the	O
last	B-Protocol
mile	I-Protocol
)	O
is	O
the	O
physical	O
link	O
or	O
circuit	O
that	O
connects	O
from	O
the	O
demarcation	B-Architecture
point	I-Architecture
of	O
the	O
customer	O
premises	O
to	O
the	O
edge	O
of	O
the	O
common	O
carrier	O
or	O
telecommunications	O
service	O
provider	O
's	O
network	O
.	O
</s>
<s>
At	O
the	O
edge	O
of	O
the	O
carrier	O
access	O
network	O
in	O
a	O
traditional	O
public	O
telephone	O
network	O
,	O
the	O
local	B-Architecture
loop	I-Architecture
terminates	O
in	O
a	O
circuit	O
switch	O
housed	O
in	O
an	O
incumbent	O
local	O
exchange	O
carrier	O
or	O
telephone	O
exchange	O
.	O
</s>
<s>
Traditionally	O
,	O
the	O
local	B-Architecture
loop	I-Architecture
was	O
an	O
electrical	O
circuit	O
in	O
the	O
form	O
of	O
a	O
single	O
pair	O
of	O
conductors	O
from	O
the	O
telephone	O
on	O
the	O
customer	O
's	O
premises	O
to	O
the	O
local	O
telephone	O
exchange	O
.	O
</s>
<s>
Hence	O
party	B-Architecture
line	I-Architecture
service	I-Architecture
was	O
often	O
given	O
to	O
residential	O
customers	O
to	O
minimise	O
the	O
number	O
of	O
local	B-Architecture
loops	I-Architecture
required	O
.	O
</s>
<s>
Usually	O
all	O
these	O
circuits	O
went	O
into	O
aerial	O
or	O
buried	O
cables	O
with	O
a	O
twisted	O
pair	O
for	O
each	O
local	B-Architecture
loop	I-Architecture
nearer	O
the	O
exchange	O
,	O
see	O
outside	O
plant	O
.	O
</s>
<s>
Modern	O
implementations	O
may	O
include	O
a	O
digital	B-Application
loop	I-Application
carrier	I-Application
system	O
segment	O
or	O
fiber	B-Architecture
optic	I-Architecture
transmission	O
system	O
.	O
</s>
<s>
The	O
local	B-Architecture
loop	I-Architecture
may	O
terminate	O
at	O
a	O
circuit	O
switch	O
owned	O
by	O
a	O
competitive	O
local	O
exchange	O
carrier	O
and	O
housed	O
in	O
a	O
point	O
of	O
presence	O
(	O
POP	O
)	O
,	O
which	O
typically	O
is	O
an	O
incumbent	O
local	O
exchange	O
carrier	O
telephone	O
exchange	O
.	O
</s>
<s>
A	O
local	B-Architecture
loop	I-Architecture
supports	O
voice	O
and/or	O
data	O
communications	O
applications	O
in	O
the	O
following	O
ways	O
:	O
</s>
<s>
variants	O
of	O
digital	O
subscriber	B-Architecture
line	I-Architecture
(	O
DSL	O
)	O
.	O
</s>
<s>
The	O
term	O
"	O
local	B-Architecture
loop	I-Architecture
"	O
is	O
sometimes	O
used	O
for	O
any	O
"	O
last	B-Protocol
mile	I-Protocol
"	O
connection	O
to	O
the	O
customer	O
,	O
regardless	O
of	O
technology	O
or	O
intended	O
purpose	O
.	O
</s>
<s>
Local	B-Architecture
loop	I-Architecture
interrelations	O
in	O
this	O
sense	O
include	O
:	O
</s>
<s>
Optical	O
or	O
fiber	B-Architecture
optics	I-Architecture
services	O
.	O
</s>
