<s>
Etherloop	B-Protocol
is	O
a	O
kind	O
of	O
DSL	O
technology	O
that	O
combines	O
the	O
features	O
of	O
Ethernet	O
and	O
DSL	O
.	O
</s>
<s>
Etherloop	B-Protocol
uses	O
half-duplex	O
transmission	O
,	O
and	O
as	O
such	O
,	O
is	O
less	O
susceptible	O
to	O
interference	O
caused	O
by	O
poor	O
line	O
quality	O
,	O
bridge	B-Architecture
taps	I-Architecture
,	O
etc	O
.	O
</s>
<s>
Also	O
,	O
etherloop	B-Protocol
modems	O
can	O
train	O
up	O
through	O
line	B-Algorithm
filters	I-Algorithm
(	O
although	O
it	O
is	O
not	O
recommended	O
to	O
do	O
this	O
)	O
.	O
</s>
<s>
Etherloop	B-Protocol
has	O
been	O
deployed	O
by	O
various	O
internet	O
service	O
providers	O
in	O
areas	O
where	O
the	O
loop	O
length	O
is	O
very	O
long	O
or	O
line	O
quality	O
is	O
poor	O
.	O
</s>
<s>
Some	O
Etherloop	B-Protocol
modems	O
(	O
those	O
made	O
by	O
Elastic	O
Networks	O
)	O
offer	O
a	O
"	O
Central	O
Office	O
mode	O
"	O
,	O
in	O
which	O
two	O
modems	O
are	O
connected	O
back	O
to	O
back	O
over	O
a	O
phone	O
line	O
and	O
used	O
as	O
a	O
LAN	B-General_Concept
extension	O
.	O
</s>
