<s>
Dead	B-Protocol
Peer	I-Protocol
Detection	I-Protocol
(	O
DPD	O
)	O
is	O
a	O
method	O
of	O
detecting	O
a	O
dead	O
Internet	B-Protocol
Key	I-Protocol
Exchange	I-Protocol
(	O
IKE	O
)	O
peer	O
.	O
</s>
<s>
The	O
method	O
uses	O
IPsec	B-Protocol
traffic	O
patterns	O
to	O
minimize	O
the	O
number	O
of	O
messages	O
required	O
to	O
confirm	O
the	O
availability	O
of	O
a	O
peer	O
.	O
</s>
