<s>
A	O
110	B-Device
block	I-Device
is	O
a	O
type	O
of	O
punch-down	B-Protocol
block	I-Protocol
used	O
to	O
terminate	O
runs	O
of	O
on-premises	B-Protocol
wiring	I-Protocol
in	O
a	O
structured	O
cabling	O
system	O
.	O
</s>
<s>
The	O
designation	O
110	O
is	O
also	O
used	O
to	O
describe	O
a	O
type	O
of	O
insulation	B-Protocol
displacement	I-Protocol
contact	O
(	O
IDC	B-Protocol
)	O
connector	O
used	O
to	O
terminate	O
twisted	O
pair	O
cables	O
,	O
which	O
uses	O
a	O
punch-down	O
tool	O
similar	O
to	O
the	O
type	O
used	O
for	O
the	O
older	O
66	B-Architecture
block	I-Architecture
.	O
</s>
<s>
These	O
screw-terminal	O
blocks	O
have	O
been	O
slowly	O
replaced	O
by	O
110	B-Device
blocks	I-Device
and	O
connectors	O
.	O
</s>
<s>
Modern	O
homes	O
usually	O
have	O
phone	O
service	O
entering	O
the	O
house	O
to	O
a	O
single	O
110	B-Device
block	I-Device
,	O
whence	O
it	O
is	O
distributed	O
by	O
on-premises	B-Protocol
wiring	I-Protocol
to	O
outlet	O
boxes	O
throughout	O
the	O
home	O
in	O
star	B-Architecture
topology	I-Architecture
.	O
</s>
<s>
At	O
the	O
outlet	O
box	O
,	O
cables	O
are	O
attached	O
to	O
ports	O
with	O
insulation-displacement	B-Protocol
contacts	I-Protocol
(	O
IDCs	B-Protocol
)	O
,	O
and	O
those	O
ports	O
fit	O
into	O
special	O
faceplates	O
.	O
</s>
<s>
In	O
commercial	O
settings	O
,	O
this	O
style	O
of	O
home	O
run	O
or	O
star	B-Architecture
topology	I-Architecture
wiring	O
was	O
already	O
in	O
use	O
on	O
66	B-Architecture
blocks	I-Architecture
in	O
telecom	O
closets	O
and	O
switchrooms	O
.	O
</s>
<s>
The	O
110	B-Device
block	I-Device
has	O
been	O
slowly	O
replacing	O
the	O
66	B-Architecture
block	I-Architecture
,	O
especially	O
for	O
data	O
communications	O
usage	O
.	O
</s>
<s>
The	O
110	O
style	O
insulation-displacement	O
connection	O
is	O
often	O
used	O
at	O
both	O
ends	O
of	O
Networking	B-Protocol
cables	I-Protocol
such	O
as	O
Category	B-Protocol
5	I-Protocol
,	O
Category	B-Protocol
5e	I-Protocol
,	O
Category	B-Protocol
6	I-Protocol
,	O
and	O
Category	B-Protocol
6a	I-Protocol
cables	I-Protocol
which	O
run	O
through	O
buildings	O
,	O
as	O
shown	O
in	O
the	O
image	O
.	O
</s>
<s>
In	O
switch	O
rooms	O
,	O
110	B-Device
blocks	I-Device
are	O
often	O
built	O
into	O
the	O
backs	O
of	O
patch	B-Protocol
panels	I-Protocol
to	O
terminate	O
cable	O
runs	O
.	O
</s>
<s>
At	O
the	O
other	O
end	O
,	O
110	O
connections	O
may	O
be	O
used	O
with	O
keystone	B-Protocol
modules	I-Protocol
that	O
are	O
attached	O
to	O
wall	O
plates	O
.	O
</s>
<s>
110	B-Device
blocks	I-Device
are	O
preferred	O
over	O
66	B-Architecture
blocks	I-Architecture
in	O
high-speed	O
networks	O
because	O
they	O
introduce	O
less	O
crosstalk	O
and	O
many	O
are	O
certified	O
for	O
use	O
in	O
Category	B-Protocol
5	I-Protocol
,	O
Category	B-Protocol
6	I-Protocol
and	O
Category	B-Protocol
6a	I-Protocol
wiring	O
systems	O
.	O
</s>
<s>
Individual	O
Category	B-Protocol
5e	I-Protocol
and	O
better-rated	O
8P8C	O
jacks	O
(	O
keystone	O
and	O
patch	B-Protocol
panel	I-Protocol
)	O
with	O
IDC	B-Protocol
connectors	I-Protocol
commonly	O
use	O
the	O
same	O
punchdown	O
'	O
teeth	O
 '	O
dimensions	O
and	O
tools	O
as	O
a	O
full	O
size	O
110	B-Device
block	I-Device
.	O
</s>
<s>
Some	O
110	B-Device
blocks	I-Device
meet	O
specifications	O
for	O
higher	O
bandwidth	O
data	O
protocols	O
such	O
as	O
Category	B-Protocol
5	I-Protocol
and	O
higher	O
.	O
</s>
<s>
During	O
regular	O
usage	O
,	O
very	O
small	O
pieces	O
of	O
insulation	O
can	O
become	O
stuck	O
inside	O
the	O
110	B-Device
block	I-Device
contacts	O
;	O
this	O
renders	O
that	O
given	O
pair	O
unreliable	O
or	O
unusable	O
,	O
until	O
the	O
pieces	O
are	O
removed	O
.	O
</s>
<s>
The	O
wire	O
hook	O
which	O
comes	O
with	O
many	O
punch	B-Protocol
down	I-Protocol
tools	O
can	O
also	O
be	O
used	O
to	O
remove	O
wire	O
pieces	O
.	O
</s>
<s>
A	O
new	O
wire	O
inserted	O
over	O
an	O
existing	O
insulation	O
remnant	O
may	O
be	O
unreliable	O
,	O
as	O
the	O
110	O
IDC	B-Protocol
was	O
designed	O
to	O
hold	O
only	O
a	O
single	O
wire	O
per	O
contact	O
.	O
</s>
<s>
For	O
testing	O
it	O
is	O
more	O
difficult	O
to	O
reliably	O
connect	O
to	O
a	O
working	O
circuit	O
on	O
a	O
110	B-Device
block	I-Device
than	O
on	O
older	O
style	O
blocks	O
.	O
</s>
