<s>
Virtual	B-Protocol
concatenation	I-Protocol
(	O
VCAT	O
)	O
is	O
an	O
inverse	B-Protocol
multiplexing	I-Protocol
technique	O
creating	O
a	O
large	O
capacity	O
payload	O
container	O
distributed	O
over	O
multiple	O
smaller	O
capacity	O
TDM	B-Protocol
signals	O
.	O
</s>
<s>
Virtual	B-Protocol
concatenation	I-Protocol
has	O
been	O
defined	O
for	O
SONET/SDH	B-Protocol
,	O
OTN	B-Protocol
and	O
PDH	B-Protocol
path	O
signals	O
.	O
</s>
<s>
Alternate	O
SONET/SDH	B-Protocol
concatenation	O
techniques	O
are	O
contiguous	O
concatenation	O
and	O
arbitrary	O
concatenation	O
.	O
</s>
<s>
Virtual	B-Protocol
concatenation	I-Protocol
is	O
considered	O
the	O
primary	O
enhancement	O
to	O
voice	O
optimized	O
SONET/SDH	B-Protocol
,	O
in	O
order	O
to	O
support	O
the	O
transport	O
of	O
variable	O
bit	O
data	O
streams	O
.	O
</s>
<s>
Other	O
recent	O
SONET/SDH	B-Protocol
enhancements	O
include	O
Link	B-Protocol
Capacity	I-Protocol
Adjustment	I-Protocol
Scheme	I-Protocol
(	O
LCAS	B-Protocol
)	O
,	O
and	O
the	O
Generic	B-Protocol
Framing	I-Protocol
Procedure	I-Protocol
(	O
GFP	O
)	O
.	O
</s>
<s>
In	O
conjunction	O
with	O
LCAS	B-Protocol
and	O
GFP	O
,	O
Virtual	B-Protocol
Concatenation	I-Protocol
gives	O
the	O
advantage	O
of	O
splitting	O
the	O
required	O
bandwidth	O
equally	O
among	O
a	O
set	O
number	O
of	O
sub	O
paths	O
called	O
Virtual	O
Tributaries	O
(	O
VT	O
)	O
.	O
</s>
<s>
The	O
Virtual	B-Protocol
Concatenation	I-Protocol
is	O
specified	O
in	O
ITU-T	O
Recommendations	O
G.707	B-Protocol
(	O
2007	O
)	O
and	O
G.783	O
(	O
2006	O
)	O
.	O
</s>
<s>
Virtual	B-Protocol
Concatenation	I-Protocol
is	O
used	O
to	O
split	O
Sonet/SDH	B-Protocol
bandwidth	O
up	O
into	O
right-sized	O
groups	O
.	O
</s>
<s>
Sonet/SDH	B-Protocol
is	O
a	O
hierarchical	O
network	O
.	O
</s>
<s>
Several	O
Virtual	O
Tributaries	O
,	O
form	O
part	O
of	O
a	O
Virtual	B-Protocol
Concatenation	I-Protocol
Group	O
(	O
VCG	O
)	O
.	O
</s>
<s>
The	O
Virtual	B-Protocol
Concatenation	I-Protocol
protocol	O
performs	O
its	O
content	O
delivery	O
through	O
a	O
process	O
called	O
byte-interleaving	O
.	O
</s>
