1. Open discussion - MIP MEP OAM maintenance point model 11 th November. 2010 Beijing Yoshinori Koike / NTT

2. Effective maintenance capability: Quick fault localization Carrier grade means extending maintenance features and operational tools rather than adding new service functions for our customers in transport services. After starting provision of our services, quality of maintenance service is only factor defining value of carrier. Quick fault localization essential, i.e., to identify what is going on, and where, when, and how it happened. P1 Customer NE2 Customer NE1 Customer domain P2 P3P4P5P6 Carrier’s domain Misconfiguration? Traffic overload? Unexpected fault? Unidentified glitch? Lot fault? Customer misconfiguratio n Equipment fault Memory Error?

3. OAM maintenance point model in MPLS-TP Type 1) Per-node model Type 2) Per-interface model OAM packets are generated/received at both ingress and egress points (per-interface MPs, one on each side of forwarding engine) EgressIngress NE1 NE2 NE1 NE2 Two OAM maintenance models supported in MPLS-TP (per- node model and per-interface model) In per-node model, operators need to identify at which point MIP/MEP is located and understand applicable range of each OAM function within NE. MP Forwarding Engine OAM packets are generated/received at one point somewhere within an NE (not clearly specified)

4. Per-node model Per-interface model Ingressegress MIP MEP MIP Source/Destination node MEP Intermediate node MIP out MIP In FW (MIP Out) Up MEP FW UP MEP (MIP In) FW Intermediate node Source node Destination node Down MEP FW Down MEP FW Source nodeDestination node

5. An example of maintenance section in per-node model Customer| Operator's administrative | Customer Domain | Domain | Domain ------> | | <------ CE1 | PE1 P1 PE2 | CE2 | | +---+ | +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ | +---+ | | | | | | | | | | | | | | | | | | | | | | | | +---+ | +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ | +---+ | In FW Out In FW Out In FW Out | | | FWD LSP | o---------------------------> | | V-------------*-------------V | | MEP1 MIP1 MEP2 | BWD LSP | <---------------------------o | | V-------------*-------------V | | MEP1' MIP1' MEP2'| (S1) (S2) Segments not covered for maintenance Node-based diagnostic capability

6. An example of maintenance section in per-interface model Customer Operator's administrative Customer Domain Domain Domain ------->| |<------ CE1 | PE1 P1 PE2 | CE2 | | +---+ | +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ | +---+ | | | | | | | | | | | | | | | | | | | | | | | | +---+ | +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ | +---+ | In FW Out In FW Out In FW Out | | | FWD LSP | o-----------------------------------> | | V-------*------*------*-----*-------V | | MEP1 MIP1 MIP2 MIP3 MIP4 MEP2| | | BWD LSP | <-----------------------------------o | | V-------*------*------*-----*-------V | | MEP1' MIP1' MIP2' MIP3' MIP4' MEP2'| (S'1) (S'2) (S'3) (S'4) (S'5) IF-based detailed diagnostic capability All segments covered for maintenance

7. Consideration in per-node model MIP MEP Interface Forwarding Engine NE1NE2 NE3 CE1 CE2 Impossible to apply OAM tools in this segment In per-node model, some faults or degradations might not be detected within an NE, because OAM tools (both proactive and on-demand) are in-effective, if faults occur in fault-undetectable segment within an NE. If fault occurs in segment not covered by CC/CV, protection not effective. NW example (per-node model: MP is located on ingress IF)