1. MPLS-TP Ring Protection draft-weingarten-mpls-tp-ring-protection draft-ceccarelli-mpls-tp-p2mp-ring
Yaacov Weingarten
Stewart Bryant
Nurit Sprecher
Daniele Ceccarelli
Diego Caviglia

2. 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

3. Status of the drafts
Have agreed to merge the current drafts into a single “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 the need to add any new mechanisms
The proposed solutions that fulfill the requirements and achieve the behavior of the criteria defined in the TP requirements

4. 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 1:1 linear protection, turning the ring into a lower layer protected span C B A D E F
Working segment (PST)
Recovery segment (PST)

5. P2MP – Option 1 – 1+1 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 D H E F G
Working PST
Recovery PST
Cont Recovery PST

6. 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
OMS 2400
OMS 2400
DSLAM3
OMS 2400
OMS 2400 C E D
DSLAM2
p2mp working LSP (cw)
p2mp protection LSP (ccw)

7. Conclusions and Next Steps
Develop “applicability draft” to propose solutions based on existing MPLS survivability technologies that
Optimize:
The numbers of OAM Sessions,
Number of alternate labels
The bandwidth usage
Work within the labeling mechanism of MPLS-TP
There are still additional (4-5) ring protection drafts – need to unify these with the proposal some of these are very similar
Invite all authors to:
Spend the time to read our ID and check if they are fine with it
join forces and produce single draft
Final draft to WG draft