<s>
A	O
provider-independent	B-Protocol
address	I-Protocol
space	I-Protocol
(	O
PI	O
)	O
is	O
a	O
block	O
of	O
IP	B-Protocol
addresses	I-Protocol
assigned	O
by	O
a	O
regional	O
Internet	O
registry	O
(	O
RIR	O
)	O
directly	O
to	O
an	O
end-user	O
organization	O
.	O
</s>
<s>
Provider-independent	O
addresses	O
offer	O
end-users	O
the	O
opportunity	O
to	O
change	O
service	O
providers	O
without	O
renumbering	O
of	O
their	O
networks	O
and	O
to	O
use	O
multiple	O
access	O
providers	O
in	O
a	O
multi-homed	B-Protocol
configuration	O
.	O
</s>
<s>
However	O
,	O
provider-independent	O
blocks	O
may	O
increase	O
the	O
burden	O
on	O
global	O
routers	O
,	O
as	O
the	O
opportunity	O
for	O
efficient	O
route	B-Protocol
aggregation	I-Protocol
through	O
Classless	B-Protocol
Inter-Domain	I-Protocol
Routing	I-Protocol
(	O
CIDR	B-Protocol
)	O
may	O
not	O
exist	O
.	O
</s>
<s>
In	O
April	O
2009	O
RIPE	O
accepted	O
a	O
policy	O
proposal	O
of	O
January	O
2006	O
to	O
assign	O
IPv6	B-Protocol
provider-independent	O
IPv6	B-Protocol
prefixes	O
.	O
</s>
