MPLS-TP Ring Protection draft-weingarten-mpls-tp-ring-protection

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MPLS-TP Ring Protectiondraft-weingarten-mpls-tp-r
ing-protection
Yaacov Weingarten (NSN), Marco Corsi
(Altran), Stewart Bryant (Cisco), Bo Wu
(ZTE), Nurit Sprecher (NSN), Xuehui Dai
(ZTE), Daniele Ceccarelli (Ericsson), Diego
Caviglia (Ericsson), Francesco Fondelli (Ericsson)

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MPLS-TP Criteria for dedicated ring protection

• MPLS-TP Requirements identifies five criteria for
  defining a special protection mechanism for a
  specific topology
• Minimize the number of OAM entities needed to
  trigger the protection
• Minimize the number of recovery objects needed
• Minimize number of labels required
• Minimize number of control and management plane
  transactions during a recovery operation
• In presence of control plane, minimize impact of
  signaling and routing information exchanged
• Note no requirement has been identified to be
  specific to a ring topology

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Status of the drafts

• Merged the following drafts from Hiroshima
• draft-weingarten-mpls-tp-ring-protection
• draft-cecarelli-mpls-tp-p2mp-ring
• draft-yang-mpls-tp-ring-protection
• draft-liu-mpls-tp-ring-protection
• draft-dai-mpls-tp-p2mp-ring-protection
• New version of draft is presented as an
  applicability document
• Define the problem statement
• Need to address p2p and p2mp LSPs that cross a
  MPLS-TP ring
• Need to address both link failure and node
  failure in the ring
• Show how we can present solutions that are
  dependent upon existing mechanisms without need
  to add any new protocols
• The proposed solutions that fulfill the
  requirements and achieve the behavior of the
  criteria defined in the TP requirements

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P2P solution - Steering

• Trigger switching
• Run OAM sessions on PST and alternate PST from
  each node to each other node (O(2n) sessions per
  node)
• Use AIS functionality to notify ingress MEP
• Ingress node transmits protected traffic on
  working or recovery PST
• Identical to 11 linear protection, turning the
  ring into a lower layer protected span

C
B
A
D
E
F
Working segment (PST)
Recovery segment (PST)
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P2MP Option 1 11 protection

• Replicate data on both the working and recovery
  PST
• Each node needs to forward packet and examine
  local copy of stack to identify packets to egress
• Each egress decides on basis of strength of
  signal which data to use
• No need for coordination between the egress and
  ingress

C
B
A
H
D
E
F
G
Working PST
Recovery PST
Cont Recovery PST
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P2MP Option 2 ROM FRR
A

• Optimize wrapping of p2mp by configuring
  alternate paths for each protected element
• N alternate paths configured for each LSP
• Support local switching that is wrapped until
  farthest egress
• Appropriate for specific applications (e.g. Video
  distribution in metro rings)

F
B
DSLAM3
C
E
D
DSLAM2
p2mp working LSP (cw)
p2mp protection LSP (ccw)
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Action items from Hiroshima

• Developed applicability draft to propose
  solutions based on existing MPLS survivability
  technologies that
• Optimize the parameters presented in the TP
  requirements
• Work within the labeling mechanism of MPLS-TP
• Current draft unifies the proposals from 5 of the
  drafts that were previously submitted.

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Next steps

• Refine the text comments are invited
• Work toward WG adoption