<s>
T-MPLS	B-Protocol
or	O
Transport	B-Protocol
MPLS	I-Protocol
is	O
a	O
transport	O
network	O
layer	O
technology	O
that	O
uses	O
extensions	O
to	O
a	O
subset	O
of	O
the	O
existing	O
MPLS	B-Protocol
standards	O
and	O
is	O
designed	O
specifically	O
for	O
application	O
in	O
transport	O
networks	O
.	O
</s>
<s>
Work	O
to	O
define	O
T-MPLS	B-Protocol
was	O
started	O
by	O
the	O
ITU-T	O
in	O
February	O
2006	O
.	O
</s>
<s>
It	O
was	O
intended	O
specifically	O
as	O
a	O
connection-oriented	O
packet-switched	O
(	O
co-ps	O
)	O
application	O
offering	O
a	O
simpler	O
implementation	O
by	O
removing	O
MPLS	B-Protocol
features	O
that	O
are	O
not	O
relevant	O
to	O
co-ps	O
applications	O
and	O
adding	O
mechanisms	O
that	O
provide	O
support	O
of	O
critical	O
transport	O
functionality	O
.	O
</s>
<s>
ITU-T	O
ceased	O
work	O
on	O
T-MPLS	B-Protocol
in	O
December	O
2008	O
,	O
in	O
favour	O
of	O
MPLS-TP	B-Protocol
standardization	O
.	O
</s>
<s>
T-MPLS	B-Protocol
uses	O
the	O
same	O
architectural	O
principles	O
of	O
layered	O
networking	O
that	O
are	O
used	O
in	O
other	O
technologies	O
like	O
SDH	B-Protocol
and	O
OTN	B-Protocol
.	O
</s>
<s>
In	O
this	O
way	O
T-MPLS	B-Protocol
was	O
intended	O
to	O
provide	O
a	O
reliable	O
packet-based	O
technology	O
that	O
is	O
familiar	O
and	O
also	O
aligned	O
with	O
circuit-based	O
transport	O
networking	O
;	O
it	O
supports	O
current	O
organizational	O
processes	O
and	O
large-scale	O
work	O
procedures	O
.	O
</s>
<s>
T-MPLS	B-Protocol
is	O
a	O
low	O
cost	O
Layer	O
2	O
technology	O
that	O
provides	O
QoS	O
,	O
end-to-end	O
OA&M	B-Architecture
and	O
protection	O
switching	O
.	O
</s>
<s>
The	O
following	O
ITU-T	O
Recommendations	O
exist	O
for	O
T-MPLS	B-Protocol
.	O
</s>
<s>
These	O
Recommendations	O
will	O
be	O
superseded	O
(	O
i.e.	O
,	O
replaced	O
)	O
by	O
new	O
revisions	O
that	O
apply	O
to	O
MPLS-TP	B-Protocol
and	O
reference	O
the	O
joint	O
work	O
being	O
undertaken	O
by	O
the	O
ITU-T	O
and	O
IETF	O
.	O
</s>
<s>
A	O
further	O
set	O
of	O
ITU-T	O
Recommendations	O
were	O
at	O
a	O
draft	O
stage	O
when	O
work	O
on	O
T-MPLS	B-Protocol
was	O
halted	O
.	O
</s>
<s>
These	O
may	O
be	O
resumed	O
at	O
a	O
later	O
stage	O
to	O
reference	O
the	O
material	O
developed	O
as	O
part	O
of	O
the	O
MPLS-TP	B-Protocol
effort	O
.	O
</s>
<s>
After	O
IETF	O
raised	O
concerns	O
over	O
T-MPLS	B-Protocol
technology	O
,	O
mainly	O
about	O
incompatibility	O
with	O
the	O
already	O
established	O
IP/MPLS	B-Protocol
,	O
the	O
ITU-T	O
and	O
the	O
IETF	O
started	O
a	O
joint	O
activity	O
to	O
solve	O
potential	O
issues	O
.	O
</s>
<s>
A	O
new	O
activity	O
was	O
added	O
to	O
the	O
charter	O
of	O
the	O
MPLS	B-Protocol
working	O
group	O
of	O
IETF	O
.	O
</s>
