<s>
Microsoft	B-General_Concept
RPC	I-General_Concept
(	O
Microsoft	O
Remote	B-Operating_System
Procedure	I-Operating_System
Call	I-Operating_System
)	O
is	O
a	O
modified	O
version	O
of	O
DCE/RPC	B-General_Concept
.	O
</s>
<s>
Additions	O
include	O
partial	O
support	O
for	O
UCS-2	O
(	O
but	O
not	O
Unicode	O
)	O
strings	O
,	O
implicit	O
handles	O
,	O
and	O
complex	O
calculations	O
in	O
the	O
variable-length	O
string	O
and	O
structure	O
paradigms	O
already	O
present	O
in	O
DCE/RPC	B-General_Concept
.	O
</s>
<s>
MSRPC	B-General_Concept
allows	O
much	O
more	O
complex	O
constructs	O
such	O
as	O
and	O
even	O
,	O
a	O
common	O
expression	O
in	O
DCOM	B-Operating_System
IDL	O
files	O
.	O
</s>
<s>
MSRPC	B-General_Concept
was	O
used	O
by	O
Microsoft	O
to	O
seamlessly	O
create	O
a	O
client/server	O
model	O
in	O
Windows	B-Device
NT	I-Device
,	O
with	O
very	O
little	O
effort	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
Windows	B-General_Concept
Server	I-General_Concept
domains	I-General_Concept
protocols	O
are	O
entirely	O
MSRPC	B-General_Concept
based	O
,	O
as	O
is	O
Microsoft	O
's	O
DNS	B-Protocol
administrative	O
tool	O
.	O
</s>
<s>
Microsoft	B-Operating_System
Exchange	I-Operating_System
Server	I-Operating_System
5.5	O
'	O
s	O
administrative	O
front-ends	O
are	O
all	O
MSRPC	B-General_Concept
client/server	O
applications	O
,	O
and	O
its	O
MAPI	B-Protocol
was	O
made	O
more	O
secure	O
by	O
"	O
proxying	O
"	O
MAPI	B-Protocol
over	O
a	O
set	O
of	O
simple	O
MSRPC	B-General_Concept
functions	O
that	O
enable	O
encryption	O
at	O
the	O
MSRPC	B-General_Concept
layer	O
without	O
involving	O
the	O
MAPI	B-Protocol
protocol	O
.	O
</s>
<s>
MSRPC	B-General_Concept
is	O
derived	O
from	O
the	O
Distributed	B-Operating_System
Computing	I-Operating_System
Environment	I-Operating_System
1.2	O
reference	O
implementation	O
from	O
the	O
Open	B-Application
Software	I-Application
Foundation	I-Application
,	O
but	O
has	O
been	O
copyrighted	O
by	O
Microsoft	O
.	O
</s>
<s>
DCE/RPC	B-General_Concept
was	O
originally	O
commissioned	O
by	O
the	O
Open	B-Application
Software	I-Application
Foundation	I-Application
,	O
an	O
industry	O
consortium	O
to	O
set	O
vendor	O
-	O
and	O
technology-neutral	O
open	O
standards	O
for	O
computing	O
infrastructure	O
.	O
</s>
<s>
None	O
of	O
the	O
Unix	B-Application
vendors	O
(	O
now	O
represented	O
by	O
the	B-Application
Open	I-Application
Group	I-Application
)	O
,	O
wanted	O
to	O
use	O
the	O
complex	O
DCE	O
or	O
such	O
components	O
as	O
DCE/RPC	B-General_Concept
at	O
the	O
time	O
.	O
</s>
<s>
Microsoft	O
's	O
Component	B-Application
Object	I-Application
Model	I-Application
is	O
based	O
heavily	O
on	O
MSRPC	B-General_Concept
,	O
adding	O
interfaces	O
and	O
inheritance	O
.	O
</s>
<s>
The	O
marshalling	O
semantics	O
of	O
DCE/RPC	B-General_Concept
are	O
used	O
to	O
serialize	O
method	O
calls	O
and	O
results	O
between	O
processes	O
with	O
separate	O
address	O
spaces	O
,	O
albeit	O
COM	O
did	O
not	O
initially	O
allow	O
network	O
calls	O
between	O
different	O
machines	O
.	O
</s>
<s>
With	O
Distributed	B-Operating_System
Component	I-Operating_System
Object	I-Operating_System
Model	I-Operating_System
(	O
DCOM	B-Operating_System
)	O
,	O
COM	O
was	O
extended	O
to	O
software	O
components	O
distributed	O
across	O
several	O
networked	O
computers	O
.	O
</s>
<s>
DCOM	B-Operating_System
,	O
which	O
originally	O
was	O
called	O
"	O
Network	O
OLE	O
"	O
,	O
extends	O
Microsoft	O
's	O
COM	O
,	O
and	O
provides	O
the	O
communication	O
substrate	O
under	O
Microsoft	O
's	O
COM+	O
application	O
server	O
infrastructure	O
.	O
</s>
