<s>
HSMP	B-General_Concept
LSP	I-General_Concept
is	O
hub	O
&	O
spoke	O
multipoint	O
Label	O
Switched	O
Path	O
(	O
LSP	O
)	O
,	O
which	O
allows	O
traffic	O
both	O
from	O
root	O
to	O
leaf	O
through	O
point-to-multipoint	O
(	O
P2MP	O
)	O
LSP	O
and	O
also	O
leaf	O
to	O
root	O
along	O
the	O
reverse	O
path	O
.	O
</s>
<s>
That	O
means	O
traffic	O
entering	O
the	O
HSMP	B-General_Concept
LSP	I-General_Concept
from	O
application/customer	O
at	O
the	O
root	O
node	O
travels	O
downstream	O
to	O
each	O
leaf	O
node	O
,	O
exactly	O
as	O
if	O
it	O
is	O
travelling	O
downstream	O
along	O
a	O
P2MP	O
LSP	O
to	O
each	O
leaf	O
node	O
.	O
</s>
<s>
Upstream	O
traffic	O
entering	O
the	O
HSMP	B-General_Concept
LSP	I-General_Concept
at	O
any	O
leaf	O
node	O
travels	O
upstream	O
along	O
the	O
tree	O
to	O
the	O
root	O
,	O
as	O
if	O
it	O
is	O
unicast	O
to	O
the	O
root	O
.	O
</s>
<s>
HSMP	B-General_Concept
LSP	I-General_Concept
is	O
an	O
MPLS	B-Protocol
Technology	O
,	O
and	O
it	O
is	O
one	O
kind	O
of	O
multipoint	O
Label	O
Switched	O
Path	O
(	O
LSP	O
)	O
.	O
</s>
<s>
IETF	O
MPLS	B-Protocol
Working	O
Group	O
is	O
standardizing	O
the	O
HSMP	B-General_Concept
LSP	I-General_Concept
.	O
</s>
<s>
The	O
LDP	O
based	O
HSMP	B-General_Concept
LSP	I-General_Concept
is	O
standardized	O
in	O
.	O
</s>
<s>
The	O
RSVP-TE	O
based	O
HSMP	B-General_Concept
LSP	I-General_Concept
is	O
standardized	O
in	O
.	O
</s>
<s>
HSMP	B-General_Concept
LSP	I-General_Concept
could	O
be	O
used	O
in	O
various	O
scenarios	O
,	O
e.g.	O
,	O
IEEE	O
1588	O
time	O
synchronization	O
,	O
P2MP	O
LSP	O
protection	O
,	O
etc	O
.	O
</s>
