<s>
Packet	B-Protocol
Layer	I-Protocol
Protocol	I-Protocol
or	O
PLP	O
is	O
the	O
Network	B-Application
Layer	I-Application
protocol	O
for	O
the	O
X.25	B-Protocol
protocol	I-Protocol
suite	I-Protocol
.	O
</s>
<s>
PLP	O
manages	O
the	O
packet	O
exchanges	O
between	O
DTE	O
(	O
data	O
terminal	O
)	O
devices	O
across	O
VCs	B-Protocol
(	O
virtual	O
calls	O
)	O
.	O
</s>
<s>
PLP	O
also	O
can	O
be	O
used	O
on	O
ISDN	B-Protocol
using	O
Link	O
Access	O
Procedures	O
,	O
D	O
channel	O
(	O
LAPD	O
)	O
.	O
</s>
<s>
Call	O
setup	O
mode	O
is	O
used	O
to	O
create	O
VCs	B-Protocol
(	O
virtual	O
calls	O
)	O
between	O
DTE	O
devices	O
.	O
</s>
<s>
A	O
PLP	O
uses	O
the	O
14-digit	O
X.121	B-Protocol
addressing	O
scheme	O
to	O
set	O
up	O
the	O
virtual	O
call	O
.	O
</s>
<s>
Call	O
clearing	O
mode	O
is	O
used	O
to	O
end	O
sessions	O
between	O
DTE	O
devices	O
and	O
to	O
terminate	O
VCs	B-Protocol
.	O
</s>
