<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
the	O
Reliable	B-Protocol
User	I-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
(	O
RUDP	B-Protocol
)	O
is	O
a	O
transport	B-Architecture
layer	I-Architecture
protocol	O
designed	O
at	O
Bell	O
Labs	O
for	O
the	O
Plan	B-Operating_System
9	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
It	O
aims	O
to	O
provide	O
a	O
solution	O
where	O
UDP	B-Protocol
is	O
too	O
primitive	O
because	O
guaranteed-order	O
packet	B-Protocol
delivery	O
is	O
desirable	O
,	O
but	O
TCP	B-Protocol
adds	O
too	O
much	O
complexity/overhead	O
.	O
</s>
<s>
In	O
order	O
for	O
RUDP	B-Protocol
to	O
gain	O
higher	O
quality	O
of	O
service	O
,	O
RUDP	B-Protocol
implements	O
features	O
that	O
are	O
similar	O
to	O
TCP	B-Protocol
with	O
less	O
overhead	O
.	O
</s>
<s>
In	O
order	O
to	O
ensure	O
quality	O
,	O
it	O
extends	O
UDP	B-Protocol
by	O
means	O
of	O
adding	O
the	O
following	O
features	O
:	O
</s>
<s>
RUDP	B-Protocol
is	O
not	O
currently	O
a	O
formal	O
standard	O
,	O
however	O
it	O
was	O
described	O
in	O
an	O
IETF	O
Internet	O
Draft	O
in	O
1999	O
.	O
</s>
<s>
Cisco	O
in	O
its	O
Signalling	O
Link	O
Terminals	O
(	O
either	O
standalone	O
or	O
integrated	O
in	O
another	O
gateway	O
)	O
uses	O
RUDP	B-Protocol
for	O
backhauling	B-General_Concept
of	O
SS7	O
MTP3	O
or	O
ISDN	B-Protocol
signaling	O
.	O
</s>
<s>
RUDP	B-Protocol
v0	O
(	O
no	O
checksums	O
)	O
is	O
used	O
for	O
SS7	O
MTP3	O
backhaul	B-General_Concept
.	O
</s>
<s>
RUDP	B-Protocol
v1	O
(	O
with	O
checksum	O
)	O
is	O
used	O
for	O
ISDN	B-Protocol
PRI	O
backhaul	B-General_Concept
.	O
</s>
<s>
The	O
structure	O
of	O
the	O
Cisco	O
Session	O
Manager	O
used	O
on	O
top	O
of	O
RUDP	B-Protocol
is	O
also	O
different	O
.	O
</s>
<s>
Microsoft	O
introduced	O
another	O
protocol	O
which	O
it	O
named	O
R-UDP	O
and	O
used	O
it	O
in	O
its	O
MediaRoom	O
product	O
(	O
now	O
owned	O
by	O
Ericsson	O
)	O
for	O
IPTV	O
service	O
delivery	O
over	O
multicast	O
networks	O
.	O
</s>
