Transcript new-Vinod-Segment-Protection-Terminology-0509-v02.pptx

Terminology:
Segment Protection
M Vinod Kumar
Abhay Karandikar
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Topology
1
3
2
4
5
This port has FDB entry
such that the two ESPs to
DA=5 egress from the
same port
These two ports though have
shared forwarding towards DA=5,
do not have shared forwarding for
traffic from SA= 5
Topology 2
1
5
3
4
6
2
This port has FDB entry
such that the two ESPs
egress from the same port
These two ports though have
shared forwarding towards node
4, do not have shared forwarding
for traffic from node 4 to DA=5 (or
6) and vice-versa on port 43
Infrastructure
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3
2
4
5
6
Traffic over this Link/LAN can
be protected using backup
resources comprising of:
LAN 3-6, LAN 6-4 and node 6
Backup
resources
Infrastructure Segment
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3
2
4
6
Protection
Domain
5
Primary Infrastructure
Segment (resources
shown in violet colour)
Backup Infrastructure
Segment (resources
shown in cream colour)
Infrastructure Segment Protection
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3
2
4
6
Infrastructure
Segment
Protection
Domain
5
Primary Infrastructure
Segment (P-IS) has its own
fault monitoring
mechanism
Backup Infrastructure
Segment (B-IS) has its own
fault monitoring
mechanism
ISP OAM
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3
2
4
6
Infrastructure
Segment
Protection
Domain
5
The P-IS fault monitoring
is independent of TESI
fault-monitoring/OAM
The B-IS fault monitoring
is independent of TESI
fault-monitoring/OAM
P-IS Fault and Protection
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3
2
4
6
Infrastructure
Segment
Protection
Domain
5
Fault here will forward the
traffic over backup
infrastructure segment
TESIs are pre-provisioned along
the Backup Infrastructure
Segment for sub-50ms
protection switching
Data Path Fault
1
3
2
4
6
Infrastructure
Segment
Protection (ISP)
Domain
5
If TESI is misconfigured on node
3 or 4 such that it does not flow
over link 3-4, it is data-path
fault; it is out-side the scope
TESI or Data-path misconfiguration is outside
the scope of ISP
Example of Data-path Segments
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3
2
4
6
Infrastructure
Segment
Protection (ISP)
Domain
5
Examples of Data path
(DP) segmentIt is configuration that
enables flow of TESI
Many Data paths can flow over
the same Infrastructure
Segment
IS fault implies DP fault
DP fault does not imply IS fault
Types of Segments
There are two types of Segments
1. Infrastructure Segment
– LANs and intervening bridge
– Has its own Segment OAM
2. Data Path Segment
– Forwarding information configured on the bridges
– Has its own E2E OAM
Types of Segment Protection
Therefore we have two types of segment
protection
• Infrastructure Segment Protection (ISP)
– Protection of traffic from failure of LANs and
intervening bridges
• Data-path Segment Protection (DSP)
– Protection from misconfiguration of TESI or Datapath
Example of Unprotected IS
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3
2
4
6
5
Example of Infrastructure
Segment that cannot
protect the TESIs
Example of Adjacent ISP Domain- 1
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3
2
4
6
5
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Allow maintenance activities to be performed independently in
different infrastructure segment protection domain.
•
Allow maintenance activities to be performed in one segment of
a network without disabling protection in another inf. segment.
•
Localize changes in traffic distribution due to failure or
maintenance actions.
Example of Adjacent ISP Domain- 2
1
3
2
4
5
6
Allow maintenance activities to be performed independently in
different infrastructure segment protection domain.
•
Allow maintenance activities to be performed in one segment of
a network without disabling protection in another inf. segment.
•
Localize changes in traffic distribution due to failure or
maintenance actions.
Example of Adjacent ISP Domain- 3
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1
3
2
4
5
6
Allow maintenance activities to be performed independently in
different infrastructure segment protection domain.
•
Allow maintenance activities to be performed in one segment of
a network without disabling protection in another inf. segment.
•
Localize changes in traffic distribution due to failure or
maintenance actions.
Some Points to be Noted
• Segment Protection is not a replacement for
e2e TESI protection
• Primary reason- infrastructure failure in
certain parts of the network
– Some links/nodes/LANs are more prone to failure
– SPS will be enabled for only these
links/nodes/LANs
Questions?