PW Group Protection

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PW Group Protection draft-zhang-pwe3-gid-app-00.tx
t
Yang Yang HealthingHearts_at_ieee.org
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Why PW Group Protection?
Its possible that multiple PWs are
transmitted over one physical media. Therefore
when one PW fail, other PWs may fail as well.
Under this circumstance, its more effective to
do group protection instead of one by one PW
protection.
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Why not just tunnel protection?
There are cases of multiple PWs in one tunnel
some of which need protection while the others
dont. Thats why tunnel protection couldnt
replace group protection.
4 PWs are trasmitted along a tunnel. Only the
blue PWs need to be protected.
This tunnel provides backup PWs.
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Why not just tunnel protection? __Cont.
Tunnel protection only limits to a single
domain/network and couldnt provide E2E
protection for MS-PW. PW protection could work
in this scenario but it consumes more bandwidth
for continuity monitoring.
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Whats the benefit of PW Group Protection?
Faster Protection Switching When the path is
failure, the PW group will switching to
protection PW group. The PWs will be treated as a
whole. Lower bandwidth consumer of OAM
traffic To monitor the continuity, only one OAM
control channel is needed while every PW one OAM
control channel if PW group protection isnt
used.
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Consideration for MS-PW Scenario--Tunnel
Switching Mode
In tunnel switching mode, all of the PWs of a
tunnel will be switched to another tunnel.
Customer_Y
TPE_C
Customer_X
TPE_B
SPE
TPE_A
Customer_X
If miss-cross connect happens in the
intermediate router, all PWs are miss connected.
The PW group only need one control channel for
miss-cross connect detecting.
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Consideration for MS-PW Scenario--PW Switching
Mode
If PW is switched in S-PE, there maybe
miss-cross connect errors.
Customer_Y
TPE_C
Customer_X
TPE_B
SPE
TPE_A
Customer_X
If miss-cross connect happens in the
intermediate router, maybe only some of the PWs
are miss connected. Its suggested that each PWs
in the group should perform miss-cross connect
detecting.
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Thank you!
Your suggestions and/or comments are appreciated!