<s>
In	O
packet-switched	B-Protocol
computer	I-Protocol
networks	I-Protocol
,	O
a	O
jumbogram	B-Protocol
(	O
portmanteau	O
of	O
jumbo	O
and	O
datagram	B-Protocol
)	O
is	O
an	O
internet-layer	B-Protocol
packet	O
exceeding	O
the	O
standard	O
maximum	B-Protocol
transmission	I-Protocol
unit	I-Protocol
(	O
MTU	B-Protocol
)	O
of	O
the	O
underlying	O
network	O
technology	O
.	O
</s>
<s>
In	O
contrast	O
,	O
large	O
packets	O
for	O
link-layer	B-Protocol
technologies	O
are	O
referred	O
to	O
as	O
jumbo	B-Protocol
frames	I-Protocol
.	O
</s>
<s>
The	O
Total	O
Length	O
field	O
of	O
IPv4	B-Protocol
and	O
the	O
Payload	O
Length	O
field	O
of	O
IPv6	B-Protocol
each	O
have	O
a	O
size	O
of	O
16	O
bits	O
,	O
thus	O
allowing	O
data	O
of	O
up	O
to	O
.	O
</s>
<s>
This	O
theoretical	O
limit	O
for	O
the	O
Internet	B-Protocol
Protocol	I-Protocol
(	O
IP	O
)	O
MTU	B-Protocol
,	O
however	O
,	O
is	O
reached	O
only	O
on	O
networks	O
that	O
have	O
a	O
suitable	O
link	B-Protocol
layer	I-Protocol
infrastructure	O
.	O
</s>
<s>
While	O
IPv4	B-Protocol
has	O
no	O
facilities	O
to	O
exceed	O
its	O
theoretical	O
IP	O
MTU	B-Protocol
limit	O
,	O
the	O
designers	O
of	O
IPv6	B-Protocol
have	O
provided	O
a	O
protocol	O
extension	O
to	O
permit	O
packets	O
of	O
larger	O
size	O
.	O
</s>
<s>
Thus	O
,	O
in	O
the	O
context	O
of	O
IPv6	B-Protocol
,	O
a	O
jumbogram	B-Protocol
is	O
understood	O
as	O
an	O
IPv6	B-Protocol
packet	I-Protocol
carrying	O
a	O
payload	O
larger	O
than	O
.	O
</s>
<s>
An	O
optional	O
feature	O
of	O
IPv6	B-Protocol
,	O
the	O
jumbo	B-Protocol
payload	I-Protocol
option	O
,	O
allows	O
the	O
exchange	O
of	O
packets	O
with	O
payloads	O
of	O
up	O
to	O
one	O
byte	O
less	O
than	O
4	O
GiB	O
(	O
232	O
−	O
1	O
=	O
4,294,967,295	O
bytes	O
)	O
,	O
by	O
making	O
use	O
of	O
a	O
32-bit	O
length	O
field	O
.	O
</s>
<s>
Historically	O
,	O
transport	B-Architecture
layer	I-Architecture
protocols	O
,	O
such	O
as	O
the	O
Transmission	B-Protocol
Control	I-Protocol
Protocol	I-Protocol
(	O
TCP	O
)	O
and	O
the	O
User	B-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
(	O
UDP	O
)	O
,	O
include	O
data	O
size	O
parameters	O
limited	O
to	O
only	O
16	O
bits	O
(	O
length	O
,	O
urgent	O
data	O
pointer	O
)	O
.	O
</s>
<s>
The	O
support	O
for	O
IPv6	B-Protocol
jumbograms	B-Protocol
required	O
a	O
redesign	O
in	O
all	O
Transport	B-Architecture
Layer	I-Architecture
protocols	O
.	O
</s>
<s>
The	O
jumbo	B-Protocol
payload	I-Protocol
option	O
and	O
the	O
transport-layer	B-Architecture
modifications	O
are	O
described	O
in	O
RFC	O
2675	O
.	O
</s>
<s>
Since	O
after	O
a	O
number	O
of	O
years	O
IPv6	B-Protocol
jumbograms	B-Protocol
have	O
not	O
been	O
widely	O
deployed	O
,	O
some	O
have	O
proposed	O
their	O
removal	O
from	O
the	O
standards	O
.	O
</s>
