<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
packet	B-Architecture
delay	I-Architecture
variation	I-Architecture
(	O
PDV	O
)	O
is	O
the	O
difference	O
in	O
end-to-end	B-Application
one-way	B-Protocol
delay	I-Protocol
between	O
selected	O
packets	O
in	O
a	O
flow	B-Operating_System
with	O
any	O
lost	B-Protocol
packets	I-Protocol
being	O
ignored	O
.	O
</s>
<s>
The	O
effect	O
is	O
sometimes	O
referred	O
to	O
as	O
packet	B-Architecture
jitter	I-Architecture
,	O
although	O
the	O
definition	O
is	O
an	O
imprecise	O
fit	O
.	O
</s>
<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
although	O
not	O
in	O
electronics	O
,	O
usage	O
of	O
the	O
term	O
jitter	O
may	O
cause	O
confusion	O
.	O
</s>
<s>
The	O
variation	O
in	O
packet	B-Protocol
delay	I-Protocol
is	O
sometimes	O
called	O
"	O
jitter	O
"	O
.	O
</s>
<s>
In	O
this	O
document	O
we	O
will	O
avoid	O
the	O
term	O
"	O
jitter	O
"	O
whenever	O
possible	O
and	O
stick	O
to	O
delay	B-Architecture
variation	I-Architecture
which	O
is	O
more	O
precise	O
.	O
</s>
<s>
Instantaneous	O
packet	B-Architecture
delay	I-Architecture
variation	I-Architecture
is	O
the	O
difference	O
between	O
successive	O
packets	O
—	O
here	O
RFC	O
3393	O
does	O
specify	O
the	O
selection	O
criteria	O
—	O
and	O
this	O
is	O
usually	O
what	O
is	O
loosely	O
termed	O
"	O
jitter	O
"	O
,	O
although	O
jitter	O
is	O
also	O
sometimes	O
the	O
term	O
used	O
for	O
the	O
variance	O
of	O
the	O
packet	B-Protocol
delay	I-Protocol
.	O
</s>
<s>
For	O
interactive	O
real-time	O
applications	O
,	O
e.g.	O
,	O
voice	B-Application
over	I-Application
IP	I-Application
(	O
VoIP	B-Application
)	O
,	O
PDV	O
can	O
be	O
a	O
serious	O
issue	O
and	O
hence	O
VoIP	B-Application
transmissions	O
may	O
need	O
quality	O
of	O
service-enabled	O
networks	O
to	O
provide	O
a	O
high	O
quality	O
channel	O
.	O
</s>
