<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
out-of-order	B-Protocol
delivery	I-Protocol
is	O
the	O
delivery	O
of	O
data	B-Protocol
packets	I-Protocol
in	O
a	O
different	O
order	O
from	O
which	O
they	O
were	O
sent	O
.	O
</s>
<s>
Out-of-order	B-Protocol
delivery	I-Protocol
can	O
be	O
caused	O
by	O
packets	B-Protocol
following	O
multiple	O
paths	O
through	O
a	O
network	O
,	O
by	O
lower-layer	O
retransmission	B-Protocol
procedures	O
(	O
such	O
as	O
automatic	B-Error_Name
repeat	I-Error_Name
request	I-Error_Name
)	O
,	O
or	O
via	O
parallel	O
processing	O
paths	O
within	O
network	O
equipment	O
that	O
are	O
not	O
designed	O
to	O
ensure	O
that	O
packet	B-Protocol
ordering	O
is	O
preserved	O
.	O
</s>
<s>
One	O
of	O
the	O
functions	O
of	O
TCP	B-Protocol
is	O
to	O
prevent	O
the	O
out-of-order	B-Protocol
delivery	I-Protocol
of	O
data	O
,	O
either	O
by	O
reassembling	O
packets	B-Protocol
in	O
order	O
or	O
requesting	O
retransmission	B-Protocol
of	O
out-of-order	O
packets	B-Protocol
.	O
</s>
