<s>
Layer	B-Protocol
2	I-Protocol
Tunnelling	O
Protocol	O
version	O
3	O
is	O
an	O
IETF	O
standard	O
related	O
to	O
L2TP	B-Application
that	O
can	O
be	O
used	O
as	O
an	O
alternative	O
protocol	O
to	O
Multiprotocol	B-Protocol
Label	I-Protocol
Switching	I-Protocol
(	O
MPLS	B-Protocol
)	O
for	O
encapsulation	B-Protocol
of	O
multiprotocol	O
Layer	B-Protocol
2	I-Protocol
communications	O
traffic	O
over	O
IP	B-Protocol
networks	O
.	O
</s>
<s>
Like	O
L2TP	B-Application
,	O
L2TPv3	B-Protocol
provides	O
a	O
pseudo-wire	B-Protocol
service	O
,	O
but	O
scaled	O
to	O
fit	O
carrier	O
requirements	O
.	O
</s>
<s>
L2TPv3	B-Protocol
can	O
be	O
regarded	O
as	O
being	O
to	O
MPLS	B-Protocol
what	O
IP	B-Protocol
is	O
to	O
ATM	O
:	O
a	O
simplified	O
version	O
of	O
the	O
same	O
concept	O
,	O
with	O
much	O
of	O
the	O
same	O
benefit	O
achieved	O
at	O
a	O
fraction	O
of	O
the	O
effort	O
,	O
at	O
the	O
cost	O
of	O
losing	O
some	O
technical	O
features	O
considered	O
less	O
important	O
in	O
the	O
market	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
L2TPv3	B-Protocol
,	O
the	O
features	O
lost	O
are	O
teletraffic	O
engineering	O
features	O
considered	O
important	O
in	O
MPLS	B-Protocol
.	O
</s>
<s>
However	O
,	O
there	O
is	O
no	O
reason	O
these	O
features	O
could	O
not	O
be	O
re-engineered	O
in	O
or	O
on	O
top	O
of	O
L2TPv3	B-Protocol
in	O
later	O
products	O
.	O
</s>
<s>
The	O
protocol	O
overhead	O
of	O
L2TPv3	B-Protocol
is	O
also	O
significantly	O
bigger	O
than	O
MPLS	B-Protocol
.	O
</s>
