<s>
Inverse	B-Protocol
Multiplexing	I-Protocol
for	I-Protocol
ATM	I-Protocol
(	O
IMA	O
)	O
is	O
a	O
standardized	O
technology	O
used	O
to	O
transport	O
ATM	O
traffic	O
over	O
a	O
bundle	O
of	O
T1	O
or	O
E1	O
lines	O
,	O
which	O
is	O
called	O
an	O
IMA	B-Protocol
Group	I-Protocol
.	O
</s>
<s>
This	O
allows	O
for	O
gradual	O
increase	O
in	O
data	O
link	O
capacity	O
where	O
implementing	O
a	O
higher	O
capacity	O
solution	O
like	O
T3/E3	O
or	O
SONET/SDH	B-Protocol
is	O
not	O
deemed	O
feasible	O
.	O
</s>
<s>
The	O
maximum	O
number	O
of	O
lines	O
in	O
an	O
IMA	B-Protocol
Group	I-Protocol
is	O
32	O
,	O
bringing	O
the	O
total	O
data	O
rate	O
to	O
roughly	O
64	O
Mbit/s	O
.	O
</s>
<s>
IMA	O
inverse	B-Protocol
multiplexing	I-Protocol
functionality	O
requires	O
some	O
overhead	O
(	O
ICP	O
or	O
IMA	O
Control	O
Protocol	O
cells	O
,	O
typically	O
one	O
ICP	O
cell	O
in	O
every	O
IMA	O
frame	O
—	O
commonly	O
128	O
cells	O
in	O
length	O
—	O
and	O
in	O
CTC	O
or	O
Common	O
Transmit	O
Clock	O
mode	O
,	O
an	O
ICP	O
stuff	O
cell	O
must	O
be	O
inserted	O
after	O
every	O
2048	O
cells	O
)	O
,	O
and	O
an	O
IMA	O
sublayer	O
on	O
the	O
physical	B-Application
layer	I-Application
.	O
</s>
