<s>
Provider	B-Protocol
Backbone	I-Protocol
Bridge	I-Protocol
Traffic	I-Protocol
Engineering	I-Protocol
(	O
PBB-TE	B-Protocol
)	O
is	O
an	O
approved	O
telecommunications	O
networking	O
standard	O
,	O
IEEE	O
802.1Qay-2009	O
.	O
</s>
<s>
PBB-TE	B-Protocol
adapts	O
Ethernet	O
technology	O
to	O
carrier	O
class	O
transport	O
networks	O
.	O
</s>
<s>
It	O
is	O
based	O
on	O
the	O
layered	O
VLAN	B-General_Concept
tags	O
and	O
MAC-in-MAC	O
encapsulation	O
defined	O
in	O
IEEE	O
802.1ah	O
(	O
Provider	O
Backbone	O
Bridges	O
(	O
PBB	O
)	O
)	O
,	O
but	O
it	O
differs	O
from	O
PBB	O
in	O
eliminating	O
flooding	O
,	O
dynamically	O
created	O
forwarding	O
tables	O
,	O
and	O
spanning	O
tree	O
protocols	O
.	O
</s>
<s>
Compared	O
to	O
PBB	O
and	O
its	O
predecessors	O
,	O
PBB-TE	B-Protocol
behaves	O
more	O
predictably	O
and	O
its	O
behavior	O
can	O
be	O
more	O
easily	O
controlled	O
by	O
the	O
network	O
operator	O
,	O
at	O
the	O
expense	O
of	O
requiring	O
up-front	O
connection	O
configuration	O
at	O
each	O
bridge	O
along	O
a	O
forwarding	O
path	O
.	O
</s>
<s>
PBB-TE	B-Protocol
Operations	O
,	O
Administration	O
,	O
and	O
Management	O
(	O
OAM	O
)	O
is	O
usually	O
based	O
on	O
IEEE	O
802.1ag	O
.	O
</s>
<s>
It	O
was	O
initially	O
based	O
on	O
Nortel	O
's	O
Provider	B-Protocol
Backbone	I-Protocol
Transport	I-Protocol
(	O
PBT	O
)	O
.	O
</s>
<s>
PBB-TE	B-Protocol
'	O
s	O
connection-oriented	O
features	O
and	O
behaviors	O
,	O
as	O
well	O
as	O
its	O
OAM	O
approach	O
,	O
are	O
inspired	O
by	O
SDH/SONET	B-Protocol
.	O
</s>
<s>
PBB-TE	B-Protocol
can	O
also	O
provide	O
path	O
protection	O
levels	O
similar	O
to	O
the	O
UPSR	O
(	O
Unidirectional	O
Path	O
Switched	O
Ring	O
)	O
protection	O
in	O
SDH/SONET	B-Protocol
networks	O
.	O
</s>
<s>
The	O
IEEE	B-Protocol
802.1Qay	I-Protocol
PBB-TE	B-Protocol
standard	O
extends	O
the	O
functionality	O
of	O
IEEE	O
802.1ah	O
Provider	O
Backbone	O
Bridges	O
,	O
adding	O
a	O
connection-oriented	O
mode	O
using	O
point-to-point	O
trunks	O
that	O
deliver	O
resiliency	O
and	O
configurable	O
performance	O
levels	O
.	O
</s>
<s>
A	O
service	O
is	O
identified	O
by	O
an	O
I-SID	O
(	O
Backbone	O
Service	O
Instance	O
Identifier	O
)	O
and	O
each	O
service	O
is	O
associated	O
with	O
a	O
PBB-TE	B-Protocol
trunk	O
.	O
</s>
<s>
Each	O
PBB-TE	B-Protocol
trunk	O
is	O
identified	O
by	O
a	O
triplet	O
of	O
B-SA	O
,	O
B-DA	O
and	O
B-VID	O
.	O
</s>
<s>
The	O
B-VID	O
is	O
a	O
backbone	O
VLAN	B-General_Concept
identifier	O
that	O
is	O
used	O
to	O
distinguish	O
different	O
trunks	O
to	O
the	O
same	O
destination	O
.	O
</s>
<s>
The	O
management	O
system	O
configures	O
the	O
PBB-TE	B-Protocol
trunks	O
on	O
all	O
the	O
edge	O
and	O
core	O
bridges	O
by	O
creating	O
static	O
forwarding	O
database	O
entries	O
;	O
the	O
management	O
system	O
is	O
responsible	O
for	O
ensuring	O
that	O
there	O
are	O
no	O
forwarding	O
loops	O
.	O
</s>
<s>
The	O
packets	O
are	O
forwarded	O
based	O
on	O
outer	O
VLAN	B-General_Concept
ID	O
(	O
B-VID	O
)	O
and	O
Destination	O
MAC	O
address	O
(	O
B-DA	O
)	O
.	O
</s>
<s>
PBB-TE	B-Protocol
equipment	O
leverages	O
economies	O
of	O
scale	O
inherent	O
in	O
Ethernet	O
,	O
promising	O
solutions	O
that	O
are	O
30%	O
to	O
40%	O
cheaper	O
than	O
T-MPLS	B-Protocol
networks	O
with	O
identical	O
features	O
and	O
capabilities	O
,	O
giving	O
PBB-TE	B-Protocol
a	O
better	O
overall	O
return	O
on	O
investment	O
.	O
</s>
<s>
Provider	B-Protocol
Backbone	I-Protocol
Bridge	I-Protocol
Traffic	I-Protocol
Engineering	I-Protocol
was	O
originally	O
developed	O
in	O
2006	O
as	O
a	O
Nortel	O
specific	O
protocol	O
named	O
Provider	B-Protocol
Backbone	I-Protocol
Transport	I-Protocol
(	O
PBT	O
)	O
.	O
</s>
<s>
The	O
company	O
championed	O
the	O
technology	O
and	O
brought	O
it	O
to	O
the	O
IEEE	O
802.1	O
committee	O
where	O
it	O
was	O
renamed	O
to	O
PBB-TE	B-Protocol
and	O
a	O
working	O
group	O
,	O
P802.1Qay	O
,	O
was	O
chartered	O
on	O
May	O
7	O
,	O
2007	O
.	O
</s>
