PowerPoint Presentation - MPLS-TP George Swallow Cisco Systems swallow@cisco.com

MPLS TP Fault OAMdraft-sfv-mpls-tp-fault-00

George Swallowswallow@cisco.comIETF76 November, 2009

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Fault NotificationVarious server layer faults need to be communicated to their clients so that alarms can be suppressed and/or corrective action taken at the client layerThree distinct server layer faults have been identifiedAlarm Indication Signal (AIS)Link Down Indication (LDI)Lock Report (LKR)These fault OAM messages are sent from server layer MEPs to client layer MEPs to report the occurrence of a faultThe fault OAM messages are sent in the direction away from the fault

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Sending Fault OAM MessagesMEPs exist at link interfaces (server layer) over which MPLS-TP LSPs (client layer) are cross connectedNote that this includes an MPLS-TP tunnel interfaces if it were used as a linkA MEP is aware of all of its xconnected MPLS-TP LSPs via configuration or signalingWhen a fault occurs on a link, the MEP associated with the link interface sends fault messages on each of the xconnected LSPs

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Fault Generation (LDI example)MEP

PE1P2P3PE4TP-LSP Physical Links SkTP LSP 1 is routed PE1 P2 P3 PE4 Link P2 - P3 failsAt P2 IF Down detected by MEP L0; At P3 IF Down detected by MEP L1MEP L0 sends LDI to MEP So; MEP L1 sends LDI to MEP Sk

XIFDownIFDownLDIL1L0SoMPLS-TP LSP 1LDI

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Alarm Indication Signal (AIS)AIS may be sent whenever there is a transient defect in the server layer, e.g. during a protection switchAIS must not be sent if the server layer enters a down state (instead LDI is sent)When AIS is received by an MPLS-TP LSPs MEP it is used to suppresses alarms due to CC failure

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Link Down Indication (LDI)LDI must be sent whenever the server layer enters a down stateWhen LDI is received by an MPLS-TP LSPs MEP it is used to Suppresses alarms due to any CC failureIf no CC failure has occurred (i.e. BFD is up), transition BFD to down with a diag Path DownNote: the above behaviors are examples and are not specified in this draft

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Indicates that the Tunnel or Link has been Administratively Locked and is unavailable to carry client trafficOtherwise same as LDILock Report (LKR)

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#New ACH Codepoint with TLV Header 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 1|Version| Reserved | 0xHH MPLS-TP Fault Management | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ACH TLV Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ~ ~ zero or more ACH TLVs ~ ~ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ~ ~ MPLS-TP Fault Message ~ ~ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#AIS, LDI and LKR message format 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Vers |Flgs |R| OpCode | Refresh Timer | Total TLV Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TLVs | ~ ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

OpCode = AIS, LDI or LKRR-flag indicates removal of the faultRefresh time indicates frequency of transmission

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#ACH TLVsOptionally carries Global-ID or ICCOptionally carries IF_ID of failed interface

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Default sending behaviorOpCode set to AIS, LDI or LKRR-flag set to zero (not used)Refresh Timer set to a default valueMessage continuously transmitted until condition clears

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#OpCode set to AIS, LDI or LKRR-flag set to zero Refresh Timer set to configured valueMessage transmitted three times at one second intervalsMessage continuously transmitted according to refresh timer until condition clearsOptional Behavior

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Used when refresh timer is set longWhen fault / lock condition clearsSet R-bit to oneTransmit three times at refresh interval of 1 secOptional Clearing Behavior

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Transitioning from AIS to LDIIf the optional sending procedures are being used, the same procedures apply to LDIThe LDI message is transmitted three times at one second intervals before falling back to the advertised refresh intervalThere is no need to clear the AIS message

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Suppress alarms due to BFDOptionally propagate the Alarm (next slide)Note: propagation to TP LSPs is post phase 1 (as we are not supporting hierarchical MPLS-TP Tunnels in phase 1)

Receiving AIS

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#Next StepsAdopt as a work group draftPolish

2006 Cisco Systems, Inc. All rights reserved.Cisco ConfidentialPresentation_ID#