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Open discussion - MIP MEP OAM maintenance point model. 11 th November. 2010 Beijing Yoshinori Koike / NTT. Effective maintenance capability: Quick fault localization.
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Open discussion - MIP MEP OAM maintenance point model 11th November. 2010 Beijing Yoshinori Koike / NTT
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. Unidentified glitch? Unexpected fault? Memory Error? Customer misconfiguration Customer NE1 Customer NE2 P2 P1 P3 P4 P5 P6 Customer domain Carrier’s domain Customer domain Lot fault? Misconfiguration? Equipment fault Traffic overload?
OAM maintenance point model in MPLS-TP • 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. NE1 NE2 Type 1) Per-node model OAM packets are generated/received at one point somewhere within an NE (not clearly specified) NE2 NE1 Ingress Egress MP Type 2) Per-interface model Forwarding Engine OAM packets are generated/received at both ingress and egress points (per-interface MPs, one on each side of forwarding engine)
MIP MIP In MIP out FW Intermediate node Intermediate node Up MEP (MIP Out) (MIP In) UP MEP FW FW MEP Destination node Source node Down MEP Down MEP FW FW Source/Destination node Source node Destination node
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)<==========================> Node-based diagnostic capability Segments not covered for maintenance
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
Consideration in per-node model • 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) CE1 NE1 NE2 NE3 CE2 Interface Impossible to apply OAM tools in this segment Impossible to apply OAM tools in this segment Forwarding Engine MIP MEP