Joint ITU-T/IEEE Workshop
on The Future of Ethernet Transport
(Geneva, 28 May 2010)
PBB-TE Infrastructure Protection
Switching Operation
Bob Sultan,
Huawei Technologies
Geneva, 28 May 2010
Topics
Review PBB-TE Forwarding
The Infrastructure Segment and IPG
Monitoring the Segment
Provisioning an IPG
Infrastructure Protection Switching
Geneva, 28 May 2010
2
PBB-TE Forwarding (ESP)
FDB D
Filtering Database (FDB) B
<DA, VID> Port Out
<E, 7>
P1
<DA, VID> Port Out
<E, 7>
P2
P2
ESP X
A
P1
P3
B
P1
P2
FDB C
P2
C
P3
<DA, VID> Port Out
<E, 7>
P3
D
P1
E
P3
Ethernet Switched Path (ESP) forwarding
is based on provisioned 2-tuple
<Destination MAC, VLAN Identifier> and
associated outbound local port;
Geneva, 28 May 2010
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PBB-TE Forwarding (TESI)
FDB D
Filtering Database (FDB) B
<DA, VID> Port Out
<E, 7>
P1
<DA, VID> Port Out
<E, 7>
P2
<A, 8>
ESP x
A
P1
P3
P1
B
P2
P1
P2
FDB C
<A, 8>
P2
P2
C
P3
<DA, VID> Port Out
<E, 7>
P3
<A, 8>
P1
D
P3
P1
TESI
ESP y
E
A pair of counterdirectional congruent PtP
ESPs form a PtP Traffic Engineered Service
Instance (TESI);
IPS also applies to linear portions of PtMP
4
Geneva,
28 May 2010
TESIs;
Segment
ESP x
A
P2
P1
B
P3
P1
P2
P2
C
P3
D
P1
P3
P1
E
P1
F
P2
G
P1
P2
H
P2
A segment is specified by a sequence of
ports:
Green: B.P2 – C.P1 – C.P3 – D.P2
Red: F.P2 – G.P1 – G.P2 – H.P2
Bridge terminating a segment contains
exactly one port associated with that
Geneva,
28 May 2010
segment;
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Segment Monitoring
CCM
CCM
Green MEP
Green MEP
Green Segment MA
A
B
C
D
E
The state of an Infrastructure Segment is
monitored by a Maintenance Association
(MA) specific to that Segment;
Distinct type of MA; not the same as the
PBB-TE MA associated with a TESI;
Terminates at PBP vs. CBP;
Geneva, 28
May 2010 MEPs vs. Up MEPs;
Down
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Infrastructure Protection Group (IPG)
I
J
SEB
A
B
SEB
C
Working Segment
D
IPG
<J, 11>
<E, 7>
E
IPG
<I, 9>
F
G
H
<A, 6>
Non-overlapping segments having the same pair of
segment endpoint bridges (SEB) form an IPG;
A Bridge maintains a table for each IPG terminating
in that Bridge (just one shown in this figure);
The table contains a list of 2-tuples representing
traffic provisioned to follow one of the Infrastructure
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Geneva, 28 May 2010
Segments which is known as the Working Segment;
Protection Segment
I
J
SEB
A
P2
B
IPG
WS: P2
PS: P3
<J, 11>
<E, 7>
P3
F
P2
C
Working Segment
Protection Segment
G
SEB
D
P3
H
E
IPG
WS: P2
PS: P3
<I, 9>
<A, 6>
The Protection Segment provides an
alternate path for traffic associated with the
listed 2-tuples for the IPG;
The IPG maintains the local port numbers
associated with the Working and Protection
8
Segments
respectively;
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28 May 2010
Protection Segment Provisioning
FDB B
<DA, VID> Port Out
I
P4
A
P1
IPG
WS: P2
PS: P3
<J, 11>
<E, 7>
B
<E, 7>
<A, 8>
P2
P1
<J, 11>
<I, 9>
P2
P4
J
P2
P2
C
P3
D
P3
P1
F
P2
G
FDB F
H
E
IPG
WS: P2
PS: P3
<I, 9>
<A, 6>
<DA, VID> Port Out
<E, 7>
<A, 8>
P2
P1
<J, 11>
<I, 9>
P2
P1
Same list of 2-tuples at F, G, H; but
provisioned as if traffic was forwarded on
Geneva, 28 May 2010
Protection Segment;
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Infrastructure Protection Switching
FDB D
FDB B
<DA, VID> Port Out
<DA, VID> Port Out
I
<E, 7>
<A, 8>
P3
P2
P1
<E, 7>
<A, 8>
P1
P2
P3
<J, 11>
<I, 9>
P2
P3
P4
<J, 11>
<I, 9>
P4
P2
P3
P4
A
IPG
WS: P2
PS: P3
<J, 11>
<E, 7>
P1
B
P2
C
P3
X
F
G
P4
P2
D
P3
P1
P2
J
H
E
P1
IPG
WS: P2
PS: P3
<I, 9>
<A, 6>
Protection switch triggered by detection of
state change in IPG Segment or manually;
Requires FDB update only at endpoint
bridges;
10
Geneva,
28 May 2010 only entries with 2-tuple in IPG list;
Update
Further Points
The IPS State Machine is identical to the TESI
Protection State Machine
Except for the lowest-level functions that update the FDB
outbound port values instead of changing the mapping
from backbone service instance to BVID;
The TESI Protection State Machine is similar, but not
identical, to the G.8031 State Machine;
IPS specifies optional M:1 protection, deployed by
using an alternate Protection Segment when a
Protection of higher priority is not available;
IPS supports the nesting of IPGs but this requires
appropriate provisioning of hold-off timer values;
Further, the MA associated with the outer IPG must be
provisioned to be protection switched by the inner IPG
when a failure of the inner IPG occurs;
Geneva, 28 May 2010
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Thank You
Geneva, 28 May 2010
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