<s>
IOS	B-Device
XR	I-Device
is	O
a	O
release	O
train	O
of	O
Cisco	O
Systems	O
 '	O
widely	O
deployed	O
Internetwork	B-Protocol
Operating	I-Protocol
System	I-Protocol
(	O
IOS	B-Protocol
)	O
,	O
used	O
on	O
their	O
high-end	O
Network	O
Convergence	O
System	O
(	O
NCS	O
)	O
and	O
carrier-grade	O
routers	B-Protocol
such	O
as	O
the	O
ASR	B-Protocol
9000	I-Protocol
series	O
and	O
Carrier	B-Protocol
Routing	I-Protocol
System	I-Protocol
series	O
of	O
routers	B-Protocol
.	O
</s>
<s>
According	O
to	O
Cisco	O
's	O
product	O
literature	O
,	O
IOS	B-Device
XR	I-Device
shares	O
very	O
little	O
infrastructure	O
with	O
the	O
other	O
IOS	B-Protocol
trains	O
,	O
and	O
is	O
instead	O
built	O
upon	O
a	O
"	O
preemptive	B-Operating_System
,	O
memory	B-General_Concept
protected	I-General_Concept
,	O
multitasking	B-Operating_System
,	O
microkernel-based	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
"	O
.	O
</s>
<s>
The	O
microkernel	B-Operating_System
was	O
formerly	O
provided	O
by	O
QNX	B-Operating_System
;	O
versions	O
6.0	O
onwards	O
use	O
the	O
Wind	O
River	O
Linux	B-Operating_System
distribution	O
.	O
</s>
<s>
IOS	B-Device
XR	I-Device
aims	O
to	O
provide	O
the	O
following	O
advantages	O
over	O
the	O
earlier	O
IOS	B-Protocol
trains	O
:	O
</s>
<s>
IOS	B-Device
XR	I-Device
was	O
announced	O
along	O
with	O
the	O
CRS-1	B-Protocol
in	O
May	O
2004	O
.	O
</s>
<s>
An	O
example	O
BGP	O
configuration	O
for	O
IOS	B-Protocol
and	O
IOS	B-Device
XR	I-Device
is	O
shown	O
.	O
</s>
<s>
More	O
examples	O
can	O
be	O
found	O
in	O
the	O
Cisco	O
document	O
Converting	O
Cisco	B-Protocol
IOS	I-Protocol
Configurations	O
to	O
Cisco	B-Device
IOS	I-Device
XR	I-Device
Configurations	O
.	O
</s>
